I know UDF in legacy sql, but UDF need you pass whole row into function, and return whole record, and UDF can't put into select section, this is not real function I need, Is Bigquery Legacy SQL can write function like Standard SQL? (can put into select or where section)
thanks :)
This functionality is only supported in Standard SQL (and as Elliott mentions in the comments, is unlikely to be added to Legacy SQL because it is being phased out).
Related
I'm working in a project where I have been explicitly required to not use T-SQL syntax. The application we are using supports T-SQL but we are not allowed to use it to avoid potential migration issues.
My question is: is the SELECT ... INTO statement T-SQL or SQL? If it is T-SQL, is there a specific SQL query to copy an existing table into a new one? (I have tried with CREATE TABLE AS .. FROM but it doesn't work).
Sounds like a very basic question but I haven't been able to find the answer anywhere. Thus, in addition to the question above, it would be very helpful to know if there is a guide/dictionary/website that collects only the standard SQL syntax.
Thanks!
I think they recommend you to use ANSI SQL, instead of T-SQL (SQL Server) or PL-SQL (ORACLE). Considering it as common requirement, every database vendor provide their own way of implementing this requirement. When you use ANSI SQL, you will not have migration issues, when you move from one database vendor to another database vendor.
SQL SERVER
SELECT * INTO new_table
FROM existing_table
ORACLE & ANSI-SQL
CREATE TABLE new_table
AS SELECT * FROM existing_table
is SELECT INTO TSQL or SQL?
Neither. The MySQL documentation claims that SELECT INTO is a Sybase extension to standard sql. As such I don't think you can accurately say it's either of these, but you can say that it's neither. It is indeed used in T-SQL, as well as some other database vendor products, to create a table from a query. The SQL standard says that queries with that goal should be formed as CREATE TABLE blah AS SELECT .... Oracle/MySQL, for example, use the standard form though you can see them use SELECT INTO in a different context, to assign data to variables in stored procedures
If you want to avoid use of this non standard syntax when creating and populating a table then you'll have to:
CREATE TABLE blah (column spec to match query output)
INSERT blah (select query here)
But then you run into nuances like "sqlserver calls it datetime/datetime2 but oracle calls it date/timestamp"
And ultimately you'll probably get into a situation where you just can't use one form of sql to do all you want..
I'd imagine most libraries that do data access on multiple underlying databases have mechanisms to use vendor specific terminology where required
From the answers, it appears you might need to specify which SELECT INTO you're talking about. The other answers seem to suggest there exists some kind of SELECT ... INTO <table-name> when there is also a kind of SELECT ... INTO <local-variable-name list>. The latter is used in embedded SQL for making SQL interact with variables of the host language program. I'm not certain but that variant may also be used in the part of the SQL language that deals with procedures written in SQL (the SQL/PSM part of the standard).
A "reference" that covers "only the standard SQL syntax" is, in principle, the ISO standard document itself, only available by purchase from ISO (and yes, it's ISO not ANSI - ANSI does nothing more than rubberstamping the ISO document after removing all the names of non-US contributors). And not the easiest kind of literature. There are "draft" versions floating around on the internet that might deviate from the published final standards. E.g. http://www.wiscorp.com/sql200n.zip. Note that this is a SQL:2008 draft. Current standard version is SQL:2011. And it's several thousands of pages, so I guess that covers your question "Is all the syntax covered in w3schools standard SQL". (Hint : no)
CREATE TEMPORARY FUNCTION
s2id(lit FLOAT64,
low FLOAT64,
level FLOAT64)
RETURNS STRING
LANGUAGE js AS """
return litLowToId(lit,low,level);
"""
OPTIONS
(library="test.js");
Big query is highlighting the lit part without telling me why. It just says encountered "" in line 2. What is happening here?
Big query is highlighting the lit part without telling me why. It just says encountered "" in line 2. What is happening here?
The reason you are getting above error in UI is because you are using Legacy SQL
Switch to Standard SQL (uncheck Use Legacy SQL checkbox in Options Panel [in Classic UI] or check Standard SQL dialect radiobox [in new UI] )
Alternatively you can just add below line to the very top (as a first line) of your whole code
See Enabling Standard SQL for more details
#standardSQL
In addition you have to provided a valid path - something like below
library="gs://my-bucket/path/to/test.js"
And finally, you need to have actual query below your function
How do I convert this standard sql to legacy sql code in bigquery?
I strongly recommend you to stay with BigQuery Standard SQL
In case you you locked by existing legacy sql code - you might rather want to migrate your sql query from legacy to standard instead
In any case UDF for BigQuery legacy and standard dialect are quite different - see Differences in user-defined JavaScript functions
I'm trying the following query from the BigQuery Standard SQL documentation:
SELECT DATE_DIFF(DATE '2010-07-07', DATE '2008-12-25', DAY) as days_diff;
https://cloud.google.com/bigquery/docs/reference/standard-sql/functions-and-operators#date_diff
However, I'm receiving the following error from the UI:
Error: Encountered " "\'2010-07-07\' "" at line 1, column 23. Was expecting: ")" ... [Try using standard SQL (https://cloud.google.com/bigquery/docs/reference/standard-sql/enabling-standard-sql)]
This is a simple copy and paste from the doc into the web UI Query Editor.
Any idea on how to resolve this?
Below are examples for respectively BigQuery Legacy SQL and Standard SQL
Make sure you try code as it is in answer below - not just second lines but 2(both) lines including first line that looks like comment - but in reality important part of query as it controls which SQL dialect will be in effect!
#legacySQL
SELECT DATEDIFF(DATE('2010-07-07'), DATE('2008-12-25')) AS days_diff
and
#standardSQL
SELECT DATE_DIFF(DATE '2010-07-07', DATE '2008-12-25', DAY) AS days_diff
both returns result as below
Row days_diff
1 559
Ideally, you should consider migrating to Standard SQL
Although the answer has already been provided in the comments to your questions and by Mikhail in the other answer, let me share with you a complete answer that hopefully addresses all your doubts:
ERROR MESSAGE
As explained in the error message you are getting, [Try using standard SQL (...)]. You are trying to run this sample using Legacy SQL (which instead would use the DATEDIFF function). You are actually right, you are running the exact same query provided in the documentation, but the issue here is that the documentation you are using is for Standard SQL (the preferred query language in BigQuery), but you are instead using Legacy SQL (the default language in the old UI, the one you are using).
CHANGE THE QUERY LANGUAGE IN USE
First of all, I would like to remark the importance of using Standard SQL instead of Legacy SQL, as the former adds new functionalities and is the current recommended language to use with BigQuery. You can see the whole list of comparisons in the documentation, but if you are starting with BigQuery, I would just go straight away with Standard SQL.
Now, that being clarified, in order to use Standard SQL instead of Legacy SQL, you can have a look at the documentation here, but let me summarize the available options for you:
In the BigQuery UI, you can toggle the Use legacy SQL option inside
the Show options menu. If this option is marked, you will be using
Legacy SQL; and if it is not, you will be using Standard SQL.
You can use a prefix in your query, like #standardSQL or #legacySQL, which would ignore the default configuration and use the language you specify with this option. As an example on how to use it, please have a look at the other answer by Mikhail, who shared with you a couple of examples using prefixes to identify the language in use. You should copy the complete query (including the prefix) in the UI, and you will see that it works successfully.
Finally, as suggested by Elliott, you can use the new UI, which has just recently released in Beta access. You can access it through this link https://console.cloud.google.com/bigquery instead of the old link https://bigquery.cloud.google.com that you were using until now. You can find more information about the new BigQuery Web UI in this other linked page too.
I have some sql statements, which i am using for Oracle. This sql statements are used by a programm from me.
I want to support Oracle and SQL-Server with my program without having different sql statements for Oracle and SQL-Server.
Which alternative can i use for the specific Oracle SQL-Statements:
to_char(FIELDNAME, 'YYYY')
to_char(FIELDNAME, 'YYYYMMDD')
to_char(FIELDNAME, 'DD.MM.YYYY')
The sql statements have to work for Oracle and SQL-Server.
Even if at a first glance the SQL implementation from two different vendors looks similar, when working with real life enterprise applications you will stumble upon a large number of differences, and I am only talking about SQL, when comparing PL/SQL with T-SQL there is hardly any resemblance left.
When trying to reduce the usage of two databases to only common functionality, you will loose a lot of their power, you could as well use a txt file on the file system.
One elegant solution, as someone already suggested, would be to leave the columns in the database as DATE data type and extract your data in the application code that stands above the database, if any. For example, in Java, you will map your database DATE columns to java.sql.Date no matter if that date comes from Oracle or from SQL Server.
Still, if you want to get your formatted data from the database, you could create separate columns that hold the formatted date, for example :
FIELDNAME | FIELDNAME_YYYY | FIELDNAME_YYYYMMDD | FIELDNAME_DDMMYYYY
I don't think there are common functions to do what you want. Oracle supports the ANSI standard extract() function for extracting date parts. SQL Server has separate functions for YEAR(), MONTH(), and DAY(). Oracle uses TO_CHAR(); SQL Server uses CONVERT().
One option is to define the functions YEAR(), MONTH(), and DAY() in Oracle and then use string concatenation (via the CONCAT()) function to combine the data. Or, write specific functions in each database for what you want to do. Or, perhaps, someone has implemented TO_CHAR() in SQL Server and you can grab the code from the web.
Finally i found a solution. Maybe its useful some other people too.
You can set the input format for a date...
Oracle: ALTER SESSION SET NLS_DATE_FORMAT = 'DD.MM.YYYY'
SQL-Server: SET DATEFORMAT dmy
I am attempting to translate the following Informatica code to the equivalent SQL scripts. I am a little stuck as I am not familiar with Informatica and would appreciate any assistance.
The original informatica code reads as follows:
LTRIM(RTRIM(SUBSTR(COV_REINS_CONCAT_BK,11, INSTR(COV_REINS_CONCAT_BK, '|',1,3)-INSTR(COV_REINS_CONCAT_BK, '|',1,2)-1 ))) || 'C'
select LTRIM(RTRIM(SUBSTR(COV_REINS_CONCAT_BK,11,INSTR(COV_REINS_CONCAT_BK,'|',1,3)
-INSTR(COV_REINS_CONCAT_BK,'|',1,2)-1 )))||'C' from TABLE;
Above script will work fine in Oracle. Please replace table with your table name.
It becomes increasingly difficult to port such expressions that make extensive use of INSTR function using the occurrence parameter.
Maybe it's easier to create in your MS-SQL database an INSTR equivalent function that supports the occurrence parameter. See how to create the dbo.INSTR function here.
On this same site you can also see a table with more function equivalences from Oracle to MS-SQL.
Then the expression from the comment becomes much easier to translate:
LTRIM(RTRIM(SUBSTRING(COV_REINS_CONCAT_BK,11,dbo.INSTR(COV_REINS_CONCAT_BK,'|',1,3)
-dbo.INSTR(COV_REINS_CONCAT_BK,'|',1,2)-1 )))+'C'
Here SUBSTR became SUBSTRING, and INSTR became dbo.INSTR and concatenation || was changed to +.
The SUBSTR() and instr() functions are from the Informatica Transformation Language. IMHO it has its roots in function names from Oracle and MSSQL / Sybase function names. This is why it doesn't translate directly to either but is similar. The functions are very well documented in the online help. You'll need to review the switches in the INSTR() function for case sensitivity and the like to ensure their parallel can be written correctly in another tool. The numbers may translate to different things and in some of the Informatica functions the end arguments can be omitted such as, in the SUBSTR() function, meaning that the SUBSTR() will take effect from the numbered position to the end of the string regardless of length. The typing of the port in Informatica can affect the result too, although in this case, the combined function is performing a trim at the end.
SUBSTR() and INSTR() functions are not MS SQL Server functions. I'm guessing the code snippet is Oracle's PL/SQL. Try resources such as http://www.dba-oracle.com/oracle_news/2005_12_16_sql_syntax_differences.htm