Converting SAS EG Data Step to Spark SQL - apache-spark-sql

I'm trying to convert the following Data Step from SAS EG to SPARK SQL
data work.Test;
set WORK.PROGRAM3;
by Year Month Day;
if first.Month then HLProfit=0;
HLProfit+HighLevelProfit;
if first.Month then UnearnedRev=0;
UnearnedRev + UnearnedRevenue_Total;
run;
I'm getting the following error when trying to run the data function using Spark SQL.
ParseException:
mismatched input 'data' expecting {'(', 'SELECT', 'FROM', 'ADD', 'DESC', 'WITH', 'VALUES', 'CREATE', 'TABLE', 'INSERT', 'DELETE', 'DESCRIBE', 'EXPLAIN', 'SHOW', 'USE', 'DROP', 'ALTER', 'MAP', 'SET', 'RESET', 'START', 'COMMIT', 'ROLLBACK', 'REDUCE', 'REFRESH', 'CLEAR', 'CACHE', 'UNCACHE', 'DFS', 'TRUNCATE', 'ANALYZE', 'LIST', 'REVOKE', 'GRANT', 'LOCK', 'UNLOCK', 'MSCK', 'EXPORT', 'IMPORT', 'LOAD'}
Appreciate if any of you can give some direction on this as I am new to this.
The expected output will be first day of the month will have HLProfit=0 and UnearnedRev=0, and then this will gradually add up as the no of days increases.
Thanks :)


I managed to get the output I want using the code below:
PROGRAM3 = spark.sql(""" SELECT *,
SUM(HighLevelProfit) OVER(partition by Year,
Month ORDER BY Day, Month, Year) AS HLProfit,
SUM(UnearnedRevenue_Total)
OVER(partition by Year, Month ORDER BY Day, Month, Year) AS UnearnedRev
FROM TEST""")

Related

commenting in spark sql

How can I comment multiple lines in spark-sql
%sql
/*
select * from database.tablename
where condition
*/
gives me the following error
Error in SQL statement:
ParseException:
mismatched input '/' expecting {'(', 'CONVERT', 'COPY', 'OPTIMIZE', 'ADD', 'ALTER', 'ANALYZE', 'CACHE', 'CLEAR', 'COMMENT', 'COMMIT', 'CREATE', 'DELETE', 'DESC', 'DESCRIBE', 'DFS', 'DROP', 'EXPLAIN', 'EXPORT', 'FROM', 'GRANT', 'IMPORT', 'INSERT', 'LIST', 'LOAD', 'LOCK', 'MAP', 'MERGE', 'MSCK', 'REDUCE', 'REFRESH', 'REPLACE', 'RESET', 'REVOKE', 'ROLLBACK', 'SELECT', 'SET', 'SHOW', 'START', 'TABLE', 'TRUNCATE', 'UNCACHE', 'UNLOCK', 'UPDATE', 'USE', 'VALUES', 'WITH'}(line 1, pos 0)

For single line comment we should use -- and for multiline /* comments */.
Actually comment is working in your case, problem is - spark ignores those comments after that it looks for sql commands but you didn't specify any.
screenshot from databricks
Below code will throw error.
spark.sql(
"""
| /* comment..1
| comment..2 */
|""")
.show()
but this works perfectly, since spark got the actual sql command to process.
spark.sql(
"""
| /* comment..1
| comment..2 */
| select current_date
|""")
.show()

couldn't test it:
/* This should be a comment
over multiple lines */
EDIT:
If this doesn't work, try:
/** Definitely a multilined
* comment
*/

Elasticsearch SQL filtering by #timestamp not working

I am trying to create an elastic query for a Kibana canvas entry and need to be able to filter by the #timestamp field.
This is the query I have tried that I thought would work from other answers to this problem:
SELECT count(DISTINCT app) as counter FROM "snapshot*" where \"#timestamp\" >= '2020-11-01' and \"#timestamp\" <= '2021-11-01'
But I instead get this error back:
[essql] > Couldn't parse Elasticsearch SQL query. You may need to add
double quotes to names containing special characters. Check your query
and try again. Error: [parsing_exception] line 1:76: extraneous input
'' expecting {'(', 'ANALYZE', 'ANALYZED', 'CASE', 'CAST', 'CATALOGS',
'COLUMNS', 'CONVERT', 'CURRENT_DATE', 'CURRENT_TIME',
'CURRENT_TIMESTAMP', 'DAY', 'DEBUG', 'EXECUTABLE', 'EXISTS',
'EXPLAIN', 'EXTRACT', 'FALSE', 'FIRST', 'FORMAT', 'FULL', 'FUNCTIONS',
'GRAPHVIZ', 'HOUR', 'INTERVAL', 'LAST', 'LEFT', 'LIMIT', 'MAPPED',
'MATCH', 'MINUTE', 'MONTH', 'NOT', 'NULL', 'OPTIMIZED', 'PARSED',
'PHYSICAL', 'PLAN', 'RIGHT', 'RLIKE', 'QUERY', 'SCHEMAS', 'SECOND',
'SHOW', 'SYS', 'TABLES', 'TEXT', 'TRUE', 'TYPE', 'TYPES', 'VERIFY',
'YEAR', '{FN', '{D', '{T', '{TS', '{GUID', '+', '-', '*', '?', STRING,
INTEGER_VALUE, DECIMAL_VALUE, IDENTIFIER, DIGIT_IDENTIFIER,
QUOTED_IDENTIFIER, BACKQUOTED_IDENTIFIER}
I'm not sure what else I can try as I've only seen the accepted answer to be to put #timestamp as "#timestamp" and it doesn't work for me.
Any help would be appreciated

Try as 'timestamp', replacing "timestamp", just single quotes.

Reading a text file using Spark and inserting the value on spark sql

from pyspark import SparkContext
from pyspark import SparkConf
lines = sc.textFile("s3://test_bucket/txt/testing_consol.txt")
llist = lines.collect()
for lines in llist:
final_query = spark.sql("""{0}
""".format(lines))
This is what inside the txt file:
select * from test_table
where id=1
I'm having the error message:
"\nmismatched input 'where' expecting {'(', 'SELECT', 'FROM', 'ADD',
'DESC', 'WITH', 'VALUES', 'CREATE', 'TABLE', 'INSERT', 'DELETE',
'DESCRIBE', 'EXPLAIN', 'SHOW', 'USE', 'DROP', 'ALTER', 'MAP', 'SET',
'RESET', 'START', 'COMMIT', 'ROLLBACK', 'REDUCE', 'REFRESH', 'CLEAR',
'CACHE', 'UNCACHE', 'DFS', 'TRUNCATE', 'ANALYZE', 'LIST', 'REVOKE',
'GRANT', 'LOCK', 'UNLOCK', 'MSCK', 'EXPORT', 'IMPORT', 'LOAD'}(line 1,
pos 0)\n\n== SQL ==\nwhere id=1\n^^^\n"
The spark sql works if I change the content of the txt file into a single line:
select * from test_table where id=1
It seems like the spark sql could only recognize the first line and not the succeeding line.

If you just merge the query lines it should work:
llist = ' '.join(lines.collect())
final_query = spark.sql(llist)

Just to read the query, creating a rdd is not at a option.
You should pass the text file containing query to spark driver using --files parameter
then read the file using python open command and pass your query to spark sql.
To read small files just to pass query is not at all recommended using spark.

BigQuery join and UDF

How can I join two tables in a select statement in which I also use a UDF? I stored the SQL query and UDF function in two files that I call via the bq command line. However, when I run it, I get the following error:
BigQuery error in query operation: Error processing job
'[projectID]:bqjob_[error_number]':
Table name cannot be resolved: dataset name is missing.
Note that I'm logged in the correct project via the gcloud auth method.
My SQL statement:
SELECT
substr(date,1,6) as date,
device,
channelGroup,
COUNT(DISTINCT CONCAT(fullVisitorId,cast(visitId as string))) AS sessions,
COUNT(DISTINCT fullVisitorId) AS users,
FROM
defaultChannelGroup(
SELECT
a.date,
a.device.deviceCategory AS device,
b.hits.page.pagePath AS page,
a.fullVisitorId,
a.visitId,
a.trafficSource.source AS trafficSourceSource,
a.trafficSource.medium AS trafficSourceMedium,
a.trafficSource.campaign AS trafficSourceCampaign
FROM FLATTEN(
SELECT date,device.deviceCategory,trafficSource.source,trafficSource.medium,trafficSource.campaign,fullVisitorId,visitID
FROM
TABLE_DATE_RANGE([datasetname.ga_sessions_],TIMESTAMP('2016-10-01'),TIMESTAMP('2016-10-31'))
,hits) as a
LEFT JOIN FLATTEN(
SELECT hits.page.pagePath,hits.time,visitID,fullVisitorId
FROM
TABLE_DATE_RANGE([datasetname.ga_sessions_],TIMESTAMP('2016-10-01'),TIMESTAMP('2016-10-31'))
WHERE
hits.time = 0
and trafficSource.medium = 'organic'
,hits) as b
ON a.fullVisitorId = b.fullVisitorId AND a.visitID = b.visitID
)
GROUP BY
date,
device,
channelGroup
ORDER BY sessions DESC
where I replaced my datasetname with the correct name of course;
and some of the UDF (which works with another query):
function defaultChannelGroup(row, emit)
{
function output(channelGroup) {
emit({channelGroup:channelGroup,
fullVisitorId: row.fullVisitorId,
visitId: row.visitId,
device: row.device,
date: row.date
});
}
computeDefaultChannelGroup(row, output);
}
bigquery.defineFunction(
'defaultChannelGroup',
['date', 'device', 'page', 'trafficSourceMedium', 'trafficSourceSource', 'trafficSourceCampaign', 'fullVisitorId', 'visitId'],
//['device', 'page', 'trafficSourceMedium', 'trafficSourceSource', 'trafficSourceCampaign', 'fullVisitorId', 'visitId'],
[{'name': 'channelGroup', 'type': 'string'},
{'name': 'fullVisitorId', 'type': 'string'},
{'name': 'visitId', 'type': 'integer'},
{'name': 'device', 'type': 'string'},
{'name': 'date', 'type': 'string'}
],
defaultChannelGroup
);

The select statements within the FLATTEN function needed to be in brackets.
Ran the bq command in the shell:
bq query --udf_resource=udf.js "$(cat query.sql)"
query.sql contains the following scripts:
SELECT
substr(date,1,6) as date,
device,
channelGroup,
COUNT(DISTINCT CONCAT(fullVisitorId,cast(visitId as string))) AS sessions,
COUNT(DISTINCT fullVisitorId) AS users,
COUNT(DISTINCT transactionId) as orders,
CAST(SUM(transactionRevenue)/1000000 AS INTEGER) as sales
FROM
defaultChannelGroup(
SELECT
a.date as date,
a.device.deviceCategory AS device,
b.hits.page.pagePath AS page,
a.fullVisitorId as fullVisitorId,
a.visitId as visitId,
a.trafficSource.source AS trafficSourceSource,
a.trafficSource.medium AS trafficSourceMedium,
a.trafficSource.campaign AS trafficSourceCampaign,
a.hits.transaction.transactionRevenue as transactionRevenue,
a.hits.transaction.transactionID as transactionId
FROM FLATTEN((
SELECT date,device.deviceCategory,trafficSource.source,trafficSource.medium,trafficSource.campaign,fullVisitorId,visitID,
hits.transaction.transactionID, hits.transaction.transactionRevenue
FROM
TABLE_DATE_RANGE([datasetname.ga_sessions_],TIMESTAMP('2016-10-01'),TIMESTAMP('2016-10-31'))
),hits) as a
LEFT JOIN FLATTEN((
SELECT hits.page.pagePath,hits.time,trafficSource.medium,visitID,fullVisitorId
FROM
TABLE_DATE_RANGE([datasetname.ga_sessions_],TIMESTAMP('2016-10-01'),TIMESTAMP('2016-10-31'))
WHERE
hits.time = 0
and trafficSource.medium = 'organic'
),hits) as b
ON a.fullVisitorId = b.fullVisitorId AND a.visitID = b.visitID
)
GROUP BY
date,
device,
channelGroup
ORDER BY sessions DESC
and udf.js contains the following function (the 'computeDefaultChannelGroup' function is not included):
function defaultChannelGroup(row, emit)
{
function output(channelGroup) {
emit({channelGroup:channelGroup,
date: row.date,
fullVisitorId: row.fullVisitorId,
visitId: row.visitId,
device: row.device,
transactionId: row.transactionId,
transactionRevenue: row.transactionRevenue,
});
}
computeDefaultChannelGroup(row, output);
}
bigquery.defineFunction(
'defaultChannelGroup',
['date', 'device', 'page', 'trafficSourceMedium', 'trafficSourceSource', 'trafficSourceCampaign', 'fullVisitorId', 'visitId', 'transactionId', 'transactionRevenue'],
[{'name': 'channelGroup', 'type': 'string'},
{'name': 'date', 'type': 'string'},
{'name': 'fullVisitorId', 'type': 'string'},
{'name': 'visitId', 'type': 'integer'},
{'name': 'device', 'type': 'string'},
{'name': 'transactionId', 'type': 'string'},
{'name': 'transactionRevenue', 'type': 'integer'}
],
defaultChannelGroup
);
Ran without error and matched the data in Google Analytics.

Regex / Parse PostgreSQL names

Going through PostgreSQL Names and Identifiers, I'm trying to figure out the following:
Is it possible to implement a regular expression (or parse it otherwise) to check whether a PostgreSQL name / identifier needs to be wrapped in double-quotes or not? And if possible, also to check if it is a Unicode-style name or not.
I need to inject an identifier name into an SQL query, and I would like to wrap this into double quotes only if the name needs it, because I read that adding quotes where they are not needed in fact changes the name format (see updates below).
UPDATE-1:
Ultimately, I need to implement the following function:
function prepareSQLName(name) {
if (/* this is a regular name*/) {
return name;
}
if (/* this is a unicode name */) {
return 'U&"' + name + '"';
} else {
/* needs double quotes only */
return '"' + name + '"';
}
}
One of the major points of concern - processing non-English names. For example, the following is a perfectly valid PostgreSQL (in Russian) that doesn't require wrapping anything into double quotes:
create table жирафы(вес int, рост int, возраст int, имя text);
select имя, вес from жирафы order by рост;
UPDATE-2:
Examples of why it is such a big deal...
CREATE TABLE Test1(name text);
-- can be queried as:
SELECT * FROM Test1
SELECT * FROM test1
SELECT * FROM "test1"
-- but not as:
SELECT * FROM "Test1"
another one:
CREATE TABLE "Test2"(name text);
-- can be queried only as:
SELECT * FROM "Test2"
And it gets even trickier for Unicode-formatted names, ones that require U& in front.

var XRegExp = require('xregexp');
var isUnquotedIdentifier = new XRegExp('^[\pL_][\pL\pM_0-9$]*$');
var reservedWords = new Set(['A', 'ABORT', 'ABS', 'ABSENT', 'ABSOLUTE', 'ACCESS', 'ACCORDING', 'ACTION', 'ADA', 'ADD', 'ADMIN', 'AFTER', 'AGGREGATE', 'ALL', 'ALLOCATE', 'ALSO', 'ALTER', 'ALWAYS', 'ANALYSE', 'ANALYZE', 'AND', 'ANY', 'ARE', 'ARRAY', 'ARRAY_AGG', 'ARRAY_MAX_CARDINALITY', 'AS', 'ASC', 'ASENSITIVE', 'ASSERTION', 'ASSIGNMENT', 'ASYMMETRIC', 'AT', 'ATOMIC', 'ATTRIBUTE', 'ATTRIBUTES', 'AUTHORIZATION', 'AVG', 'BACKWARD', 'BASE64', 'BEFORE', 'BEGIN', 'BEGIN_FRAME', 'BEGIN_PARTITION', 'BERNOULLI', 'BETWEEN', 'BIGINT', 'BINARY', 'BIT', 'BIT_LENGTH', 'BLOB', 'BLOCKED', 'BOM', 'BOOLEAN', 'BOTH', 'BREADTH', 'BY', 'C', 'CACHE', 'CALL', 'CALLED', 'CARDINALITY', 'CASCADE', 'CASCADED', 'CASE', 'CAST', 'CATALOG', 'CATALOG_NAME', 'CEIL', 'CEILING', 'CHAIN', 'CHAR', 'CHARACTER', 'CHARACTERISTICS', 'CHARACTERS', 'CHARACTER_LENGTH', 'CHARACTER_SET_CATALOG', 'CHARACTER_SET_NAME', 'CHARACTER_SET_SCHEMA', 'CHAR_LENGTH', 'CHECK', 'CHECKPOINT', 'CLASS', 'CLASS_ORIGIN', 'CLOB', 'CLOSE', 'CLUSTER', 'COALESCE', 'COBOL', 'COLLATE', 'COLLATION', 'COLLATION_CATALOG', 'COLLATION_NAME', 'COLLATION_SCHEMA', 'COLLECT', 'COLUMN', 'COLUMNS', 'COLUMN_NAME', 'COMMAND_FUNCTION', 'COMMAND_FUNCTION_CODE', 'COMMENT', 'COMMENTS', 'COMMIT', 'COMMITTED', 'CONCURRENTLY', 'CONDITION', 'CONDITION_NUMBER', 'CONFIGURATION', 'CONFLICT', 'CONNECT', 'CONNECTION', 'CONNECTION_NAME', 'CONSTRAINT', 'CONSTRAINTS', 'CONSTRAINT_CATALOG', 'CONSTRAINT_NAME', 'CONSTRAINT_SCHEMA', 'CONSTRUCTOR', 'CONTAINS', 'CONTENT', 'CONTINUE', 'CONTROL', 'CONVERSION', 'CONVERT', 'COPY', 'CORR', 'CORRESPONDING', 'COST', 'COUNT', 'COVAR_POP', 'COVAR_SAMP', 'CREATE', 'CROSS', 'CSV', 'CUBE', 'CUME_DIST', 'CURRENT', 'CURRENT_CATALOG', 'CURRENT_DATE', 'CURRENT_DEFAULT_TRANSFORM_GROUP', 'CURRENT_PATH', 'CURRENT_ROLE', 'CURRENT_ROW', 'CURRENT_SCHEMA', 'CURRENT_TIME', 'CURRENT_TIMESTAMP', 'CURRENT_TRANSFORM_GROUP_FOR_TYPE', 'CURRENT_USER', 'CURSOR', 'CURSOR_NAME', 'CYCLE', 'DATA', 'DATABASE', 'DATALINK', 'DATE', 'DATETIME_INTERVAL_CODE', 'DATETIME_INTERVAL_PRECISION', 'DAY', 'DB', 'DEALLOCATE', 'DEC', 'DECIMAL', 'DECLARE', 'DEFAULT', 'DEFAULTS', 'DEFERRABLE', 'DEFERRED', 'DEFINED', 'DEFINER', 'DEGREE', 'DELETE', 'DELIMITER', 'DELIMITERS', 'DENSE_RANK', 'DEPTH', 'DEREF', 'DERIVED', 'DESC', 'DESCRIBE', 'DESCRIPTOR', 'DETERMINISTIC', 'DIAGNOSTICS', 'DICTIONARY', 'DISABLE', 'DISCARD', 'DISCONNECT', 'DISPATCH', 'DISTINCT', 'DLNEWCOPY', 'DLPREVIOUSCOPY', 'DLURLCOMPLETE', 'DLURLCOMPLETEONLY', 'DLURLCOMPLETEWRITE', 'DLURLPATH', 'DLURLPATHONLY', 'DLURLPATHWRITE', 'DLURLSCHEME', 'DLURLSERVER', 'DLVALUE', 'DO', 'DOCUMENT', 'DOMAIN', 'DOUBLE', 'DROP', 'DYNAMIC', 'DYNAMIC_FUNCTION', 'DYNAMIC_FUNCTION_CODE', 'EACH', 'ELEMENT', 'ELSE', 'EMPTY', 'ENABLE', 'ENCODING', 'ENCRYPTED', 'END', 'END-EXEC', 'END_FRAME', 'END_PARTITION', 'ENFORCED', 'ENUM', 'EQUALS', 'ESCAPE', 'EVENT', 'EVERY', 'EXCEPT', 'EXCEPTION', 'EXCLUDE', 'EXCLUDING', 'EXCLUSIVE', 'EXEC', 'EXECUTE', 'EXISTS', 'EXP', 'EXPLAIN', 'EXPRESSION', 'EXTENSION', 'EXTERNAL', 'EXTRACT', 'FALSE', 'FAMILY', 'FETCH', 'FILE', 'FILTER', 'FINAL', 'FIRST', 'FIRST_VALUE', 'FLAG', 'FLOAT', 'FLOOR', 'FOLLOWING', 'FOR', 'FORCE', 'FOREIGN', 'FORTRAN', 'FORWARD', 'FOUND', 'FRAME_ROW', 'FREE', 'FREEZE', 'FROM', 'FS', 'FULL', 'FUNCTION', 'FUNCTIONS', 'FUSION', 'G', 'GENERAL', 'GENERATED', 'GET', 'GLOBAL', 'GO', 'GOTO', 'GRANT', 'GRANTED', 'GREATEST', 'GROUP', 'GROUPING', 'GROUPS', 'HANDLER', 'HAVING', 'HEADER', 'HEX', 'HIERARCHY', 'HOLD', 'HOUR', 'ID', 'IDENTITY', 'IF', 'IGNORE', 'ILIKE', 'IMMEDIATE', 'IMMEDIATELY', 'IMMUTABLE', 'IMPLEMENTATION', 'IMPLICIT', 'IMPORT', 'IN', 'INCLUDING', 'INCREMENT', 'INDENT', 'INDEX', 'INDEXES', 'INDICATOR', 'INHERIT', 'INHERITS', 'INITIALLY', 'INLINE', 'INNER', 'INOUT', 'INPUT', 'INSENSITIVE', 'INSERT', 'INSTANCE', 'INSTANTIABLE', 'INSTEAD', 'INT', 'INTEGER', 'INTEGRITY', 'INTERSECT', 'INTERSECTION', 'INTERVAL', 'INTO', 'INVOKER', 'IS', 'ISNULL', 'ISOLATION', 'JOIN', 'K', 'KEY', 'KEY_MEMBER', 'KEY_TYPE', 'LABEL', 'LAG', 'LANGUAGE', 'LARGE', 'LAST', 'LAST_VALUE', 'LATERAL', 'LEAD', 'LEADING', 'LEAKPROOF', 'LEAST', 'LEFT', 'LENGTH', 'LEVEL', 'LIBRARY', 'LIKE', 'LIKE_REGEX', 'LIMIT', 'LINK', 'LISTEN', 'LN', 'LOAD', 'LOCAL', 'LOCALTIME', 'LOCALTIMESTAMP', 'LOCATION', 'LOCATOR', 'LOCK', 'LOCKED', 'LOGGED', 'LOWER', 'M', 'MAP', 'MAPPING', 'MATCH', 'MATCHED', 'MATERIALIZED', 'MAX', 'MAXVALUE', 'MAX_CARDINALITY', 'MEMBER', 'MERGE', 'MESSAGE_LENGTH', 'MESSAGE_OCTET_LENGTH', 'MESSAGE_TEXT', 'METHOD', 'MIN', 'MINUTE', 'MINVALUE', 'MOD', 'MODE', 'MODIFIES', 'MODULE', 'MONTH', 'MORE', 'MOVE', 'MULTISET', 'MUMPS', 'NAME', 'NAMES', 'NAMESPACE', 'NATIONAL', 'NATURAL', 'NCHAR', 'NCLOB', 'NESTING', 'NEW', 'NEXT', 'NFC', 'NFD', 'NFKC', 'NFKD', 'NIL', 'NO', 'NONE', 'NORMALIZE', 'NORMALIZED', 'NOT', 'NOTHING', 'NOTIFY', 'NOTNULL', 'NOWAIT', 'NTH_VALUE', 'NTILE', 'NULL', 'NULLABLE', 'NULLIF', 'NULLS', 'NUMBER', 'NUMERIC', 'OBJECT', 'OCCURRENCES_REGEX', 'OCTETS', 'OCTET_LENGTH', 'OF', 'OFF', 'OFFSET', 'OIDS', 'OLD', 'ON', 'ONLY', 'OPEN', 'OPERATOR', 'OPTION', 'OPTIONS', 'OR', 'ORDER', 'ORDERING', 'ORDINALITY', 'OTHERS', 'OUT', 'OUTER', 'OUTPUT', 'OVER', 'OVERLAPS', 'OVERLAY', 'OVERRIDING', 'OWNED', 'OWNER', 'P', 'PAD', 'PARAMETER', 'PARAMETER_MODE', 'PARAMETER_NAME', 'PARAMETER_ORDINAL_POSITION', 'PARAMETER_SPECIFIC_CATALOG', 'PARAMETER_SPECIFIC_NAME', 'PARAMETER_SPECIFIC_SCHEMA', 'PARSER', 'PARTIAL', 'PARTITION', 'PASCAL', 'PASSING', 'PASSTHROUGH', 'PASSWORD', 'PATH', 'PERCENT', 'PERCENTILE_CONT', 'PERCENTILE_DISC', 'PERCENT_RANK', 'PERIOD', 'PERMISSION', 'PLACING', 'PLANS', 'PLI', 'POLICY', 'PORTION', 'POSITION', 'POSITION_REGEX', 'POWER', 'PRECEDES', 'PRECEDING', 'PRECISION', 'PREPARE', 'PREPARED', 'PRESERVE', 'PRIMARY', 'PRIOR', 'PRIVILEGES', 'PROCEDURAL', 'PROCEDURE', 'PROGRAM', 'PUBLIC', 'QUOTE', 'RANGE', 'RANK', 'READ', 'READS', 'REAL', 'REASSIGN', 'RECHECK', 'RECOVERY', 'RECURSIVE', 'REF', 'REFERENCES', 'REFERENCING', 'REFRESH', 'REGR_AVGX', 'REGR_AVGY', 'REGR_COUNT', 'REGR_INTERCEPT', 'REGR_R2', 'REGR_SLOPE', 'REGR_SXX', 'REGR_SXY', 'REGR_SYY', 'REINDEX', 'RELATIVE', 'RELEASE', 'RENAME', 'REPEATABLE', 'REPLACE', 'REPLICA', 'REQUIRING', 'RESET', 'RESPECT', 'RESTART', 'RESTORE', 'RESTRICT', 'RESULT', 'RETURN', 'RETURNED_CARDINALITY', 'RETURNED_LENGTH', 'RETURNED_OCTET_LENGTH', 'RETURNED_SQLSTATE', 'RETURNING', 'RETURNS', 'REVOKE', 'RIGHT', 'ROLE', 'ROLLBACK', 'ROLLUP', 'ROUTINE', 'ROUTINE_CATALOG', 'ROUTINE_NAME', 'ROUTINE_SCHEMA', 'ROW', 'ROWS', 'ROW_COUNT', 'ROW_NUMBER', 'RULE', 'SAVEPOINT', 'SCALE', 'SCHEMA', 'SCHEMA_NAME', 'SCOPE', 'SCOPE_CATALOG', 'SCOPE_NAME', 'SCOPE_SCHEMA', 'SCROLL', 'SEARCH', 'SECOND', 'SECTION', 'SECURITY', 'SELECT', 'SELECTIVE', 'SELF', 'SENSITIVE', 'SEQUENCE', 'SEQUENCES', 'SERIALIZABLE', 'SERVER', 'SERVER_NAME', 'SESSION', 'SESSION_USER', 'SET', 'SETOF', 'SETS', 'SHARE', 'SHOW', 'SIMILAR', 'SIMPLE', 'SIZE', 'SKIP', 'SMALLINT', 'SNAPSHOT', 'SOME', 'SOURCE', 'SPACE', 'SPECIFIC', 'SPECIFICTYPE', 'SPECIFIC_NAME', 'SQL', 'SQLCODE', 'SQLERROR', 'SQLEXCEPTION', 'SQLSTATE', 'SQLWARNING', 'SQRT', 'STABLE', 'STANDALONE', 'START', 'STATE', 'STATEMENT', 'STATIC', 'STATISTICS', 'STDDEV_POP', 'STDDEV_SAMP', 'STDIN', 'STDOUT', 'STORAGE', 'STRICT', 'STRIP', 'STRUCTURE', 'STYLE', 'SUBCLASS_ORIGIN', 'SUBMULTISET', 'SUBSTRING', 'SUBSTRING_REGEX', 'SUCCEEDS', 'SUM', 'SYMMETRIC', 'SYSID', 'SYSTEM', 'SYSTEM_TIME', 'SYSTEM_USER', 'T', 'TABLE', 'TABLES', 'TABLESAMPLE', 'TABLESPACE', 'TABLE_NAME', 'TEMP', 'TEMPLATE', 'TEMPORARY', 'TEXT', 'THEN', 'TIES', 'TIME', 'TIMESTAMP', 'TIMEZONE_HOUR', 'TIMEZONE_MINUTE', 'TO', 'TOKEN', 'TOP_LEVEL_COUNT', 'TRAILING', 'TRANSACTION', 'TRANSACTIONS_COMMITTED', 'TRANSACTIONS_ROLLED_BACK', 'TRANSACTION_ACTIVE', 'TRANSFORM', 'TRANSFORMS', 'TRANSLATE', 'TRANSLATE_REGEX', 'TRANSLATION', 'TREAT', 'TRIGGER', 'TRIGGER_CATALOG', 'TRIGGER_NAME', 'TRIGGER_SCHEMA', 'TRIM', 'TRIM_ARRAY', 'TRUE', 'TRUNCATE', 'TRUSTED', 'TYPE', 'TYPES', 'UESCAPE', 'UNBOUNDED', 'UNCOMMITTED', 'UNDER', 'UNENCRYPTED', 'UNION', 'UNIQUE', 'UNKNOWN', 'UNLINK', 'UNLISTEN', 'UNLOGGED', 'UNNAMED', 'UNNEST', 'UNTIL', 'UNTYPED', 'UPDATE', 'UPPER', 'URI', 'USAGE', 'USER', 'USER_DEFINED_TYPE_CATALOG', 'USER_DEFINED_TYPE_CODE', 'USER_DEFINED_TYPE_NAME', 'USER_DEFINED_TYPE_SCHEMA', 'USING', 'VACUUM', 'VALID', 'VALIDATE', 'VALIDATOR', 'VALUE', 'VALUES', 'VALUE_OF', 'VARBINARY', 'VARCHAR', 'VARIADIC', 'VARYING', 'VAR_POP', 'VAR_SAMP', 'VERBOSE', 'VERSION', 'VERSIONING', 'VIEW', 'VIEWS', 'VOLATILE', 'WHEN', 'WHENEVER', 'WHERE', 'WHITESPACE', 'WIDTH_BUCKET', 'WINDOW', 'WITH', 'WITHIN', 'WITHOUT', 'WORK', 'WRAPPER', 'WRITE', 'XML', 'XMLAGG', 'XMLATTRIBUTES', 'XMLBINARY', 'XMLCAST', 'XMLCOMMENT', 'XMLCONCAT', 'XMLDECLARATION', 'XMLDOCUMENT', 'XMLELEMENT', 'XMLEXISTS', 'XMLFOREST', 'XMLITERATE', 'XMLNAMESPACES', 'XMLPARSE', 'XMLPI', 'XMLQUERY', 'XMLROOT', 'XMLSCHEMA', 'XMLSERIALIZE', 'XMLTABLE', 'XMLTEXT', 'XMLVALIDATE', 'YEAR', 'YES', 'ZONE']);
function prepareSQLName(name) {
if (isUnquotedIdentifier.test(name) && !reservedWords.has(name.toUpperCase()))
return name;
// Let's quote name:
return '"' + name.replace(/"/g, '""') + '"';
}
console.log(prepareSQLName('simple')); //simple
console.log(prepareSQLName('to "quote')); //"to ""quote"
console.log(prepareSQLName('простий')); //простий
console.log(prepareSQLName('в "лапки')); //"в ""лапки"
Notes:
We need xregexp module, because built-in RegExp class doesn't support testing of Unicode categories (\pL a.k.a. p{L} and \pM a.k.a \p{M}). Still, detecting letters is not 100%-clear (see "Details on detecting letters").
List of key words is taken from here. Using this list may be non-ideal solution, as not all of these identifiers are really prohibited for use in all possible cases (i.e. sometimes it may quote table name that is allowed to be unquoted, e.g. abs). On the other hand, this task cannot be solved ideally without adding namePurpose second parameter to prepareSQLName function (as some of these identifiers are allowed for use in specific cases only).
You do not need special handling of non-ASCII, if you want non-English letters to remain non-escaped (they may be non-escaped as in SELECT "ім'я" FROM користувачі). The only thing to be checked is that identifiers containing something other than letters/digits/_/$ should be quoted (as "ім'я"). But you may also additionally escape all non-ASCII characters, if you wish:
var isUnquotedIdentifier = new RegExp('^[A-Za-z_][A-Za-z_0-9$]*$');
var reservedWords = new Set(['A', 'ABORT', 'ABS', 'ABSENT', 'ABSOLUTE', 'ACCESS', 'ACCORDING', 'ACTION', 'ADA', 'ADD', 'ADMIN', 'AFTER', 'AGGREGATE', 'ALL', 'ALLOCATE', 'ALSO', 'ALTER', 'ALWAYS', 'ANALYSE', 'ANALYZE', 'AND', 'ANY', 'ARE', 'ARRAY', 'ARRAY_AGG', 'ARRAY_MAX_CARDINALITY', 'AS', 'ASC', 'ASENSITIVE', 'ASSERTION', 'ASSIGNMENT', 'ASYMMETRIC', 'AT', 'ATOMIC', 'ATTRIBUTE', 'ATTRIBUTES', 'AUTHORIZATION', 'AVG', 'BACKWARD', 'BASE64', 'BEFORE', 'BEGIN', 'BEGIN_FRAME', 'BEGIN_PARTITION', 'BERNOULLI', 'BETWEEN', 'BIGINT', 'BINARY', 'BIT', 'BIT_LENGTH', 'BLOB', 'BLOCKED', 'BOM', 'BOOLEAN', 'BOTH', 'BREADTH', 'BY', 'C', 'CACHE', 'CALL', 'CALLED', 'CARDINALITY', 'CASCADE', 'CASCADED', 'CASE', 'CAST', 'CATALOG', 'CATALOG_NAME', 'CEIL', 'CEILING', 'CHAIN', 'CHAR', 'CHARACTER', 'CHARACTERISTICS', 'CHARACTERS', 'CHARACTER_LENGTH', 'CHARACTER_SET_CATALOG', 'CHARACTER_SET_NAME', 'CHARACTER_SET_SCHEMA', 'CHAR_LENGTH', 'CHECK', 'CHECKPOINT', 'CLASS', 'CLASS_ORIGIN', 'CLOB', 'CLOSE', 'CLUSTER', 'COALESCE', 'COBOL', 'COLLATE', 'COLLATION', 'COLLATION_CATALOG', 'COLLATION_NAME', 'COLLATION_SCHEMA', 'COLLECT', 'COLUMN', 'COLUMNS', 'COLUMN_NAME', 'COMMAND_FUNCTION', 'COMMAND_FUNCTION_CODE', 'COMMENT', 'COMMENTS', 'COMMIT', 'COMMITTED', 'CONCURRENTLY', 'CONDITION', 'CONDITION_NUMBER', 'CONFIGURATION', 'CONFLICT', 'CONNECT', 'CONNECTION', 'CONNECTION_NAME', 'CONSTRAINT', 'CONSTRAINTS', 'CONSTRAINT_CATALOG', 'CONSTRAINT_NAME', 'CONSTRAINT_SCHEMA', 'CONSTRUCTOR', 'CONTAINS', 'CONTENT', 'CONTINUE', 'CONTROL', 'CONVERSION', 'CONVERT', 'COPY', 'CORR', 'CORRESPONDING', 'COST', 'COUNT', 'COVAR_POP', 'COVAR_SAMP', 'CREATE', 'CROSS', 'CSV', 'CUBE', 'CUME_DIST', 'CURRENT', 'CURRENT_CATALOG', 'CURRENT_DATE', 'CURRENT_DEFAULT_TRANSFORM_GROUP', 'CURRENT_PATH', 'CURRENT_ROLE', 'CURRENT_ROW', 'CURRENT_SCHEMA', 'CURRENT_TIME', 'CURRENT_TIMESTAMP', 'CURRENT_TRANSFORM_GROUP_FOR_TYPE', 'CURRENT_USER', 'CURSOR', 'CURSOR_NAME', 'CYCLE', 'DATA', 'DATABASE', 'DATALINK', 'DATE', 'DATETIME_INTERVAL_CODE', 'DATETIME_INTERVAL_PRECISION', 'DAY', 'DB', 'DEALLOCATE', 'DEC', 'DECIMAL', 'DECLARE', 'DEFAULT', 'DEFAULTS', 'DEFERRABLE', 'DEFERRED', 'DEFINED', 'DEFINER', 'DEGREE', 'DELETE', 'DELIMITER', 'DELIMITERS', 'DENSE_RANK', 'DEPTH', 'DEREF', 'DERIVED', 'DESC', 'DESCRIBE', 'DESCRIPTOR', 'DETERMINISTIC', 'DIAGNOSTICS', 'DICTIONARY', 'DISABLE', 'DISCARD', 'DISCONNECT', 'DISPATCH', 'DISTINCT', 'DLNEWCOPY', 'DLPREVIOUSCOPY', 'DLURLCOMPLETE', 'DLURLCOMPLETEONLY', 'DLURLCOMPLETEWRITE', 'DLURLPATH', 'DLURLPATHONLY', 'DLURLPATHWRITE', 'DLURLSCHEME', 'DLURLSERVER', 'DLVALUE', 'DO', 'DOCUMENT', 'DOMAIN', 'DOUBLE', 'DROP', 'DYNAMIC', 'DYNAMIC_FUNCTION', 'DYNAMIC_FUNCTION_CODE', 'EACH', 'ELEMENT', 'ELSE', 'EMPTY', 'ENABLE', 'ENCODING', 'ENCRYPTED', 'END', 'END-EXEC', 'END_FRAME', 'END_PARTITION', 'ENFORCED', 'ENUM', 'EQUALS', 'ESCAPE', 'EVENT', 'EVERY', 'EXCEPT', 'EXCEPTION', 'EXCLUDE', 'EXCLUDING', 'EXCLUSIVE', 'EXEC', 'EXECUTE', 'EXISTS', 'EXP', 'EXPLAIN', 'EXPRESSION', 'EXTENSION', 'EXTERNAL', 'EXTRACT', 'FALSE', 'FAMILY', 'FETCH', 'FILE', 'FILTER', 'FINAL', 'FIRST', 'FIRST_VALUE', 'FLAG', 'FLOAT', 'FLOOR', 'FOLLOWING', 'FOR', 'FORCE', 'FOREIGN', 'FORTRAN', 'FORWARD', 'FOUND', 'FRAME_ROW', 'FREE', 'FREEZE', 'FROM', 'FS', 'FULL', 'FUNCTION', 'FUNCTIONS', 'FUSION', 'G', 'GENERAL', 'GENERATED', 'GET', 'GLOBAL', 'GO', 'GOTO', 'GRANT', 'GRANTED', 'GREATEST', 'GROUP', 'GROUPING', 'GROUPS', 'HANDLER', 'HAVING', 'HEADER', 'HEX', 'HIERARCHY', 'HOLD', 'HOUR', 'ID', 'IDENTITY', 'IF', 'IGNORE', 'ILIKE', 'IMMEDIATE', 'IMMEDIATELY', 'IMMUTABLE', 'IMPLEMENTATION', 'IMPLICIT', 'IMPORT', 'IN', 'INCLUDING', 'INCREMENT', 'INDENT', 'INDEX', 'INDEXES', 'INDICATOR', 'INHERIT', 'INHERITS', 'INITIALLY', 'INLINE', 'INNER', 'INOUT', 'INPUT', 'INSENSITIVE', 'INSERT', 'INSTANCE', 'INSTANTIABLE', 'INSTEAD', 'INT', 'INTEGER', 'INTEGRITY', 'INTERSECT', 'INTERSECTION', 'INTERVAL', 'INTO', 'INVOKER', 'IS', 'ISNULL', 'ISOLATION', 'JOIN', 'K', 'KEY', 'KEY_MEMBER', 'KEY_TYPE', 'LABEL', 'LAG', 'LANGUAGE', 'LARGE', 'LAST', 'LAST_VALUE', 'LATERAL', 'LEAD', 'LEADING', 'LEAKPROOF', 'LEAST', 'LEFT', 'LENGTH', 'LEVEL', 'LIBRARY', 'LIKE', 'LIKE_REGEX', 'LIMIT', 'LINK', 'LISTEN', 'LN', 'LOAD', 'LOCAL', 'LOCALTIME', 'LOCALTIMESTAMP', 'LOCATION', 'LOCATOR', 'LOCK', 'LOCKED', 'LOGGED', 'LOWER', 'M', 'MAP', 'MAPPING', 'MATCH', 'MATCHED', 'MATERIALIZED', 'MAX', 'MAXVALUE', 'MAX_CARDINALITY', 'MEMBER', 'MERGE', 'MESSAGE_LENGTH', 'MESSAGE_OCTET_LENGTH', 'MESSAGE_TEXT', 'METHOD', 'MIN', 'MINUTE', 'MINVALUE', 'MOD', 'MODE', 'MODIFIES', 'MODULE', 'MONTH', 'MORE', 'MOVE', 'MULTISET', 'MUMPS', 'NAME', 'NAMES', 'NAMESPACE', 'NATIONAL', 'NATURAL', 'NCHAR', 'NCLOB', 'NESTING', 'NEW', 'NEXT', 'NFC', 'NFD', 'NFKC', 'NFKD', 'NIL', 'NO', 'NONE', 'NORMALIZE', 'NORMALIZED', 'NOT', 'NOTHING', 'NOTIFY', 'NOTNULL', 'NOWAIT', 'NTH_VALUE', 'NTILE', 'NULL', 'NULLABLE', 'NULLIF', 'NULLS', 'NUMBER', 'NUMERIC', 'OBJECT', 'OCCURRENCES_REGEX', 'OCTETS', 'OCTET_LENGTH', 'OF', 'OFF', 'OFFSET', 'OIDS', 'OLD', 'ON', 'ONLY', 'OPEN', 'OPERATOR', 'OPTION', 'OPTIONS', 'OR', 'ORDER', 'ORDERING', 'ORDINALITY', 'OTHERS', 'OUT', 'OUTER', 'OUTPUT', 'OVER', 'OVERLAPS', 'OVERLAY', 'OVERRIDING', 'OWNED', 'OWNER', 'P', 'PAD', 'PARAMETER', 'PARAMETER_MODE', 'PARAMETER_NAME', 'PARAMETER_ORDINAL_POSITION', 'PARAMETER_SPECIFIC_CATALOG', 'PARAMETER_SPECIFIC_NAME', 'PARAMETER_SPECIFIC_SCHEMA', 'PARSER', 'PARTIAL', 'PARTITION', 'PASCAL', 'PASSING', 'PASSTHROUGH', 'PASSWORD', 'PATH', 'PERCENT', 'PERCENTILE_CONT', 'PERCENTILE_DISC', 'PERCENT_RANK', 'PERIOD', 'PERMISSION', 'PLACING', 'PLANS', 'PLI', 'POLICY', 'PORTION', 'POSITION', 'POSITION_REGEX', 'POWER', 'PRECEDES', 'PRECEDING', 'PRECISION', 'PREPARE', 'PREPARED', 'PRESERVE', 'PRIMARY', 'PRIOR', 'PRIVILEGES', 'PROCEDURAL', 'PROCEDURE', 'PROGRAM', 'PUBLIC', 'QUOTE', 'RANGE', 'RANK', 'READ', 'READS', 'REAL', 'REASSIGN', 'RECHECK', 'RECOVERY', 'RECURSIVE', 'REF', 'REFERENCES', 'REFERENCING', 'REFRESH', 'REGR_AVGX', 'REGR_AVGY', 'REGR_COUNT', 'REGR_INTERCEPT', 'REGR_R2', 'REGR_SLOPE', 'REGR_SXX', 'REGR_SXY', 'REGR_SYY', 'REINDEX', 'RELATIVE', 'RELEASE', 'RENAME', 'REPEATABLE', 'REPLACE', 'REPLICA', 'REQUIRING', 'RESET', 'RESPECT', 'RESTART', 'RESTORE', 'RESTRICT', 'RESULT', 'RETURN', 'RETURNED_CARDINALITY', 'RETURNED_LENGTH', 'RETURNED_OCTET_LENGTH', 'RETURNED_SQLSTATE', 'RETURNING', 'RETURNS', 'REVOKE', 'RIGHT', 'ROLE', 'ROLLBACK', 'ROLLUP', 'ROUTINE', 'ROUTINE_CATALOG', 'ROUTINE_NAME', 'ROUTINE_SCHEMA', 'ROW', 'ROWS', 'ROW_COUNT', 'ROW_NUMBER', 'RULE', 'SAVEPOINT', 'SCALE', 'SCHEMA', 'SCHEMA_NAME', 'SCOPE', 'SCOPE_CATALOG', 'SCOPE_NAME', 'SCOPE_SCHEMA', 'SCROLL', 'SEARCH', 'SECOND', 'SECTION', 'SECURITY', 'SELECT', 'SELECTIVE', 'SELF', 'SENSITIVE', 'SEQUENCE', 'SEQUENCES', 'SERIALIZABLE', 'SERVER', 'SERVER_NAME', 'SESSION', 'SESSION_USER', 'SET', 'SETOF', 'SETS', 'SHARE', 'SHOW', 'SIMILAR', 'SIMPLE', 'SIZE', 'SKIP', 'SMALLINT', 'SNAPSHOT', 'SOME', 'SOURCE', 'SPACE', 'SPECIFIC', 'SPECIFICTYPE', 'SPECIFIC_NAME', 'SQL', 'SQLCODE', 'SQLERROR', 'SQLEXCEPTION', 'SQLSTATE', 'SQLWARNING', 'SQRT', 'STABLE', 'STANDALONE', 'START', 'STATE', 'STATEMENT', 'STATIC', 'STATISTICS', 'STDDEV_POP', 'STDDEV_SAMP', 'STDIN', 'STDOUT', 'STORAGE', 'STRICT', 'STRIP', 'STRUCTURE', 'STYLE', 'SUBCLASS_ORIGIN', 'SUBMULTISET', 'SUBSTRING', 'SUBSTRING_REGEX', 'SUCCEEDS', 'SUM', 'SYMMETRIC', 'SYSID', 'SYSTEM', 'SYSTEM_TIME', 'SYSTEM_USER', 'T', 'TABLE', 'TABLES', 'TABLESAMPLE', 'TABLESPACE', 'TABLE_NAME', 'TEMP', 'TEMPLATE', 'TEMPORARY', 'TEXT', 'THEN', 'TIES', 'TIME', 'TIMESTAMP', 'TIMEZONE_HOUR', 'TIMEZONE_MINUTE', 'TO', 'TOKEN', 'TOP_LEVEL_COUNT', 'TRAILING', 'TRANSACTION', 'TRANSACTIONS_COMMITTED', 'TRANSACTIONS_ROLLED_BACK', 'TRANSACTION_ACTIVE', 'TRANSFORM', 'TRANSFORMS', 'TRANSLATE', 'TRANSLATE_REGEX', 'TRANSLATION', 'TREAT', 'TRIGGER', 'TRIGGER_CATALOG', 'TRIGGER_NAME', 'TRIGGER_SCHEMA', 'TRIM', 'TRIM_ARRAY', 'TRUE', 'TRUNCATE', 'TRUSTED', 'TYPE', 'TYPES', 'UESCAPE', 'UNBOUNDED', 'UNCOMMITTED', 'UNDER', 'UNENCRYPTED', 'UNION', 'UNIQUE', 'UNKNOWN', 'UNLINK', 'UNLISTEN', 'UNLOGGED', 'UNNAMED', 'UNNEST', 'UNTIL', 'UNTYPED', 'UPDATE', 'UPPER', 'URI', 'USAGE', 'USER', 'USER_DEFINED_TYPE_CATALOG', 'USER_DEFINED_TYPE_CODE', 'USER_DEFINED_TYPE_NAME', 'USER_DEFINED_TYPE_SCHEMA', 'USING', 'VACUUM', 'VALID', 'VALIDATE', 'VALIDATOR', 'VALUE', 'VALUES', 'VALUE_OF', 'VARBINARY', 'VARCHAR', 'VARIADIC', 'VARYING', 'VAR_POP', 'VAR_SAMP', 'VERBOSE', 'VERSION', 'VERSIONING', 'VIEW', 'VIEWS', 'VOLATILE', 'WHEN', 'WHENEVER', 'WHERE', 'WHITESPACE', 'WIDTH_BUCKET', 'WINDOW', 'WITH', 'WITHIN', 'WITHOUT', 'WORK', 'WRAPPER', 'WRITE', 'XML', 'XMLAGG', 'XMLATTRIBUTES', 'XMLBINARY', 'XMLCAST', 'XMLCOMMENT', 'XMLCONCAT', 'XMLDECLARATION', 'XMLDOCUMENT', 'XMLELEMENT', 'XMLEXISTS', 'XMLFOREST', 'XMLITERATE', 'XMLNAMESPACES', 'XMLPARSE', 'XMLPI', 'XMLQUERY', 'XMLROOT', 'XMLSCHEMA', 'XMLSERIALIZE', 'XMLTABLE', 'XMLTEXT', 'XMLVALIDATE', 'YEAR', 'YES', 'ZONE']);
function prepareSQLName(name) {
if (isUnquotedIdentifier.test(name) && !reservedWords.has(name.toUpperCase()))
return name;
// Let's quote (and possibly escape) name:
var reallyEscaped = false;
var escapedName = '';
for (var i = 0; i!=name.length; ++i) {
var charCode = name.charCodeAt(i);
if (charCode<128) {
var char = name.charAt(i);
escapedName += char=='"' ? '""' : char;
}
else {
reallyEscaped = true;
escapedName += '\\' + ('0000' + charCode.toString(16)).slice(-4);
}
}
return reallyEscaped ? 'U&"' + escapedName + '"' : '"' + escapedName + '"';
}
console.log(prepareSQLName('simple')); //simple
console.log(prepareSQLName('to "quote')); //"to ""quote"
console.log(prepareSQLName('простий')); //U&"\043f\0440\043e\0441\0442\0438\0439"
console.log(prepareSQLName('в "лапки')); //U&"\0432 ""\043b\0430\043f\043a\0438"
I recommend you to lowercase name by calling name = name.toLowerCase(); before quoting it. Without doing this you'll need to take care about the fact that hello and HeLLo would be treated as same name, but hello world and HeLLo WoRld as different (because the latter two will got quoted). But doing this will make your code incompatible with code that doesn't forcibly lowercase all names (i.e. you won't be able to access entities with non-all-lowercase names that contain something other than letter, digit, underscore or dollar sign).
Details on detecting letters:
I'm not sure about this, but AFAIK different versions of Unicode standard can have different sets of code points for letters (i.e. some code point that is considered as letter in one version of Unicode standard may be considered as non-letter by other version of Unicode standard). If that's true, you'll get weird SQL syntax error, if JavaScript considers some code point as non-English letter and therefore sends it unquoted, while PostgreSQL considers it to be non-letter at all and therefore doesn't expect it outside quotes (e.g. due to older Unicode libraries within PostgreSQL server). To overcome this, you can either forcibly quote every non-ASCII character (by replacing \pL with A-Za-z), or at least ensure that JavaScript's definition of letter isn't wider than PostgreSQL (by replacing \pL with explicit code range list for specific Unicode version like here for Unicode 6.3.0).
De facto PostgreSQL allows almost any Unicode character (except for the forbidden characters within ASCII range and invalid surrogates) to be used within unquoted identifiers -- not just letters/digits/_/$ -- and even non-ASCII whitespace and unassigned code points are in fact allowed (although official documentation says nothing about that). This is probably done to prevent future compatibility issues (e.g. the one described in the strikeout text). The reasonable behavior at our side in this case would be to send only letters/digits/_/$ to PostgreSQL in unquoted form (as official documentation suggests), but now we don't need to worry about following exact version of Unicode standard for detecting them.
The question still remaining is whether we should treat only \pL as letters, or \pL\pM* too (the former may include letter with diacritic only if it's represented by single code point, while the latter includes all kinds of letters with diacritics). De jure official documentation says nothing for this question, while de facto PostgreSQL accepts almost any Unicode character. Probably, in such case the latter is more reasonable (that's why I replaced ^[\pL_][\pL_0-9$]*$ from original version of the first code listing with ^[\pL_][\pL\pM_0-9$]*$).
Resume:
Whether to escape (U&"\044F") or not to escape ("я") a character within quoted identifier -- it's absolutely the matter of your taste (per documentation, any character except for NUL may appear non-escaped in quoted identifier, but NUL isn't allowed within identifiers anyway).
Whether to quote ("hello") or not to quote (hello) an identifier:
an identifier must be quoted if it contains any ASCII character other than English letter, digit 0 to 9, underscore sign or dollar sign, or if it starts from any ASCII character other than English letter or underscore sign;
an identifier should be quoted if it contains any non-ASCII character other than letter of any language, with or without diacritics; de facto such identifier will be accepted even without quoting, but such behavior isn't mentioned in documentation and may be changed in future;
otherwise it's your choice whether to quote an identifier or no; if you prefer case insensitivity, you may tend to first listing (which does quoting at the minimum and no escaping), if you unlike non-ASCII characters, you may tend to second listing (which quotes and escapes every non-ASCII character, even officially allowed).

Given Bobby Tables won't be rearing his ugly head, you could try something like this, which expands upon klin's good attempt:
CREATE OR REPLACE FUNCTION prepareSQLName(VARCHAR(255), BOOLEAN)
RETURNS VARCHAR(255) LANGUAGE PLPGSQL AS $$
BEGIN
IF ($2) THEN
EXECUTE 'SELECT * FROM ' || $1;
ELSE
EXECUTE 'CREATE TEMP TABLE ' || $1 || ' (ID INT) ON COMMIT DROP';
END IF;
RETURN $1;
EXCEPTION WHEN OTHERS THEN
IF LEFT($1, 1) <> '"' AND prepareSQLName('"' || $1 || '"', $2) = '"' || $1 || '"' THEN
RETURN '"' || $1 || '"';
ELSE
RETURN NULL;
END IF;
END $$;
Explanation
The question seems to include two cases:
Finding out whether an identifier is valid for an existing table
...and...
Finding out whether an identifier can be used for a new
table or column name.
Hence the second boolean parameter in the function: This determines whether an attempt is made to select from an existing table (if true) or create a new temporary table (if false) - in both cases, first using the supplied identifier (first parameter value) as-is.
If no errors occurred the function simply returns the supplied identifier. If an error occurred, a second recursive call is made to see if wrapping in quotes helps the situation. If so, the quoted version is returned. But if this also caused an error then the identifier is deemed unusable in any form and NULL is returned.
See SQL Fiddle Demo for some example usage.
Additional Findings - Unicode table names
For the record, I wanted to find out how unicode behaved and which unicode characters are and aren't acceptable in the quoted form described in the link you posted. To do this, I tried similar selects to yours and found the Test3 table created in its quoted unicode form (CREATE TABLE U&"\0054\0065\0073\0074\0033" (ID INT);) behaved exactly the same as the quoted "Test2" table.
Also tried running this to find which characters can be used:
DO $do$
DECLARE chr VARCHAR(9);
BEGIN
FOR i IN 0..9999 LOOP
chr := 'U&"\' || LPAD(CAST(i AS VARCHAR(4)), 4, '0') || '"';
IF prepareSQLName(chr, FALSE) IS NULL THEN
RAISE NOTICE 'NOT OK: %', chr;
END IF;
END LOOP;
END $do$;
It raises just one notice:
NOTICE: NOT OK: U&"\0000"
This shows the only unicode character that can't be used in a table name is the NUL character.