I am loading and inserting data into an Oracle database. When I encounter special characters that look like Chinese characters, I am getting an error like row rejected because maximum size of column was exceeded. I am not getting this error for rows which have English characters which appear to be of same length for same column. I am using SUBSTR and TRIM function but it is not working. How can I determine whether the length of a string which is in Chinese exceeds column size?
if your columns are defined as VARCHAR2(XX) [for example VARCHAR2(20)], you will receive an error if you try to insert a string that is more than XX bytes long.
The function SUBSTR calculates length in number of characters, not bytes. To select a substring in bytes, use the function SUBSTRB.
SQL> select substr('ЙЖ', 1, 2) from dual;
SUBSTR('ЙЖ',1,2)
------------------
ЙЖ
SQL> select substrb('ЙЖ', 1, 2) from dual;
SUBSTRB('ЙЖ',1,2)
-------------------
Й
Edit: As suggested by Adam, you can use character arithmetics if you define your columns and variables as VARCHAR2 (XX CHAR). In that case your columns will be able to store XX characters, in all character sets (up to a maximum of 4000 bytes if you store it in a table).
Related
I have a attribute with the data type char(256). I import the value via SQL Developer from a csv file
When the attribute gets a value with 10 characters, the remaining space gets filled with spaces.
I know that char allocates the space staticly, but does that also mean that I get a string in the format like "abc " ?
Since this make sql statements with equal operators difficult.
You are operating under a misconception; it has nothing to do with SQL Developer.
A CHAR data-type is a fixed-length string; if you do not provide a string of the full length then Oracle will right-pad the string with space (ASCII 32) characters until it has the correct length.
From the documentation:
CHAR Datatype
The CHAR datatype stores fixed-length character strings. When you create a table with a CHAR column, you must specify a string length (in bytes or characters) between 1 and 2000 bytes for the CHAR column width. The default is 1 byte. Oracle then guarantees that:
When you insert or update a row in the table, the value for the CHAR column has the fixed length.
If you give a shorter value, then the value is blank-padded to the fixed length.
If a value is too large, Oracle Database returns an error.
Oracle Database compares CHAR values using blank-padded comparison semantics.
To solve this, do not use CHAR for variable length strings and use VARCHAR2 instead.
VARCHAR2 and VARCHAR Datatypes
The VARCHAR2 datatype stores variable-length character strings. When you create a table with a VARCHAR2 column, you specify a maximum string length (in bytes or characters) between 1 and 4000 bytes for the VARCHAR2 column. For each row, Oracle Database stores each value in the column as a variable-length field unless a value exceeds the column's maximum length, in which case Oracle Database returns an error. Using VARCHAR2 and VARCHAR saves on space used by the table.
You may use varchar2 instead of char as datatype to avoid this.
Or you can trim your data in query by using rtrim(columnname) .
I have a Oracle procedure, its return query
SELECT CODE "Կադաստրային ծածկագիր", ENTAKAYANI "Ենթակայան"
FROM ELECTRIC_ENTAKAYAN_500
WHERE SDO_RELATE(GEOM,SDO_GEOM.SDO_BUFFER(
MDSYS.SDO_GEOMETRY(2001, 2400000,
MDSYS.SDO_POINT_TYPE(8451136.4,4451591.2,NULL),
NULL, NULL), 2, 0.005)
,'mask=ANYINTERACT')='TRUE'
AND rownum <= 10;
and problem this length("Կադաստրային ծածկագիր") = 20, Oracle max size length filed 30 symbol, but my string Armenian languages its > 30 symbol.
How to find an another solution?
If you are using Oracle 12cR2 you could use identifiers that are up to 128 bytes.
Database Object Naming Rules:
If COMPATIBLE is set to a value of 12.2 or higher, then names must be from 1 to 128 bytes long with these exceptions:
Names of databases are limited to 8 bytes.
Names of disk groups, pluggable databases (PDBs), rollback segments, tablespaces, and tablespace sets are limited to 30 bytes.
If an identifier includes multiple parts separated by periods, then each attribute can be up to 128 bytes long. Each period separator, as well as any surrounding double quotation marks, counts as one byte. For example, suppose you identify a column like this:
"schema"."table"."column"
The schema name can be 128 bytes, the table name can be 128 bytes, and the column name can be 128 bytes. Each of the quotation marks and periods is a single-byte character, so the total length of the identifier in this example can be up to 392 bytes.
Please keep in mind that byte != character.
SELECT /*csv*/ 1 AS "Կադաստրային ծածկագիր" FROM dual;
/*
"Կադաստրային ծածկագիր"
1
*/
And counting characters/bytes:
SELECT
length('ադաստրային ծածկագիր 1234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890') AS char#
,lengthb('ադաստրային ծածկագիր 1234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890') AS bytes#
FROM dual;
/*
CHAR# BYTES#
---------- ----------
120 138
*/
I have some large varchar values in Postgres that I want to SELECT and move somewhere else. The place they are going to uses VARCHAR(4095) so I only need at most 4095 bytes (I think that's bytes) and some of these varchars are quite big, so a performance optimization would be to SELECT a truncated version of them.
How can I do that?
Something like:
SELECT TRUNCATED(my_val, 4095) ...
I don't think it's a character length though, it needs to be a byte length?
The n in varchar(n) is the number of characters, not bytes. The manual:
SQL defines two primary character types: character varying(n) and
character(n), where n is a positive integer. Both of these types can
store strings up to n characters (not bytes) in length.
Bold emphasis mine.
The simplest way to "truncate" a string would be with left():
SELECT left(my_val, 4095)
Or just cast:
SELECT my_val::varchar(4095)
The manual once more:
If one explicitly casts a value to character varying(n) or
character(n), then an over-length value will be truncated to n
characters without raising an error. (This too is required by the SQL standard.)
Table A
Id varchar(30)
I'm trying to re-create a logic where I have to use 9 digit Ids irrespective of the actual length of the Value of the Id field.
So for instance, if the Id is of length 6, I'll need to left pad with 3 leading zeros. The actual length can be anything ranging from 1 to 9.
Any ideas how to implement this in Teradata SQL?
If the actual length is 1 to 9 characters why is the column defined as VarCar(30)?
If it was a numeric column it would be easy:
CAST(CAST(numeric_col AS FORMAT '9(9)') AS CHAR(9))
For strings there's no FORMAT like that, but depending on your release you might have an LPAD function:
LPAD(string_col, 9, '0')
Otherwise it's:
SUBSTRING('000000000' FROM CHAR_LENGTH(string_col)+1) || string_col,
If there are more than nine characters all previous calculations will return them.
If you want to truncate (or a CHAR instead of a VARCHAR result) you have to add a final CAST AS CHAR(9)
And finally, if there are leading or trailing blanks you might want to use TRIM(string_col)
I have an integer column in my table. It is product id and has values like
112233001
112233002
113311001
225577001
This numbering (AABBCCDDD) is formed of 4 parts:
AA : first level category
BB : second level category
CC : third level category
DDD : counter
I want to check condition in my SELECT statement to select rows that for example have BB = 33 and AA = 11
Please help
Would this suffice:
select x from table where field >= 113300000 and field < 113400000
SELECT * FROM YOURTABLE
WHERE
substr(PRODUCT_ID, 3, 2)='33'
AND
substr(PRODUCT_ID, 1, 2)='11'
OR
SELECT * FROM YOURTABLE
WHERE
PRODUCT_ID LIKE '11%33%'
and yes in short you have to convert to string
reference of substr
Purpose
The SUBSTR functions return a portion of char, beginning at character position, substring_length characters long. SUBSTR calculates lengths using characters as defined by the input character set. SUBSTRB uses bytes instead of characters. SUBSTRC uses Unicode complete characters. SUBSTR2 uses UCS2 code points. SUBSTR4 uses UCS4 code points.
If position is 0, then it is treated as 1.
If position is positive, then Oracle Database counts from the beginning of char to find the first character.
If position is negative, then Oracle counts backward from the end of char.
If substring_length is omitted, then Oracle returns all characters to the end of char. If substring_length is less than 1, then Oracle returns null.
char can be any of the datatypes CHAR, VARCHAR2, NCHAR, NVARCHAR2, CLOB, or NCLOB. Both position and substring_length must be of datatype NUMBER, or any datatype that can be implicitly converted to NUMBER, and must resolve to an integer. The return value is the same datatype as char. Floating-point numbers passed as arguments to SUBSTR are automatically converted to integers.
Select field from table where substr(field,,) = value
This seems like it could work. Otherwise you may have to cast them as strings and parse the values out that you need which would make your queries much slower.
SELECT *
FROM table t
WHERE t.field >= 113300000
AND t.field < 113400000
u need to use _ wildcard char -
SELECT *
FROM TABLE
WHERE
FIELD LIKE '1133_____'
here, each _ is for one char. So you need to put the same number of _ to keep the length same