DB2 Version 10.1 for Linux, UNIX, and Windows

REPLACE scalar function

Replaces all occurrences of search-string in source-string with replace-string.


                                                .-,''-------------.      
>>-REPLACE--(--source-string--,--search-string--+-----------------+--)-><
                                                '-,replace-string-'

The schema is SYSIBM. The SYSFUN version of the REPLACE function continues to be available but it is not sensitive to the database collation.

If search-string is not found in source-string, search-string is returned unchanged. A linguistically correct search is done if the Unicode database is defined with a locale-sensitive UCA-based collation and none of the source-string, search-string or replace-string arguments are defined as FOR BIT DATA. Otherwise, the search is done using a binary comparison with no special consideration for multi-byte characters.

source-string: An expression that specifies the source string. The expression must return a value that is a built-in CHAR, VARCHAR, GRAPHIC, VARGRAPHIC, numeric, or datetime data type. If the value is not a CHAR, VARCHAR, GRAPHIC, or VARGRAPHIC data type, it is implicitly cast to VARCHAR before evaluating the function.
search-string: An expression that specifies the string to be removed from the source string. The expression must return a value that is a built-in CHAR, VARCHAR, GRAPHIC, VARGRAPHIC, numeric, or datetime data type. If the value is not a CHAR, VARCHAR, GRAPHIC, or VARGRAPHIC data type, it is implicitly cast to VARCHAR before evaluating the function.
replace-string: An expression that specifies the replacement string. The expression must return a value that is a built-in CHAR, VARCHAR, GRAPHIC, VARGRAPHIC, numeric, or datetime data type. If the value is not a CHAR, VARCHAR, GRAPHIC, or VARGRAPHIC data type, it is implicitly cast to VARCHAR before evaluating the function. If the expression is an empty string or is not specified, nothing replaces the string that is removed from the source string.

The actual length of each string must be 32 672 bytes or less for character strings, or 16 336 or less for graphic strings. All three arguments must have compatible data types.

If source-string, search-string or replace-string is defined as FOR BIT DATA, the result is VARCHAR FOR BIT DATA. If source-string is a character string, the result is VARCHAR. If source-string is a graphic string, the result is VARGRAPHIC. If one argument is character FOR BIT DATA, the other arguments must not be graphic (SQLSTATE 42846).

The length attribute of the result depends on the arguments:

If the length attribute of replace-string is less than or equal to the length attribute of search-string, the length attribute of the result is the length attribute of source-string.
If the length attribute of replace-string is greater than the length attribute of search-string, the length attribute of the result is determined as follows, depending on the data type of the result:
- For VARCHAR:
  - If L1 < = 4000, the length attribute of the result is MIN(4000, (L3*(L1/L2)) + MOD(L1,L2))
  - Otherwise, the length attribute of the result is MIN(32672, (L3*(L1/L2)) + MOD(L1,L2))
- For VARGRAPHIC:
  - If L1 < = 2000, the length attribute of the result is MIN(2000, (L3*(L1/L2)) + MOD(L1,L2))
  - Otherwise, the length attribute of the result is MIN(16336, (L3*(L1/L2)) + MOD(L1,L2))
where:
- L1 is the length attribute of source-string
- L2 is the length attribute of the search-string if the search string is a string constant. Otherwise, L2 is 1.
- L3 is the length attribute of replace-string

If the result is a character string, the length attribute of the result must not exceed 32 672. If the result is a graphic string, the length attribute of the result must not exceed 16 336.

The actual length of the result is the actual length of source-string plus the number of occurrences of search-string that exist in source-string multiplied by the actual length of replace-string minus the actual length of search-string.

If the actual length of the replace-string exceeds the maximum for the return data type, an error is returned. If any argument can be null, the result can be null; if any argument is null, the result is the null value.

Examples

Example 1: Replace all occurrences of the letter 'N' in the word 'DINING' with 'VID'.
```
   VALUES CHAR (REPLACE ('DINING', 'N', 'VID'), 10)
```
The result is the string 'DIVIDIVIDG'.
Example 2: In a Unicode database with case-insensitive collation CLDR181_LEN_S1, replace the word 'QUICK' with the word 'LARGE'.
```
VALUES REPLACE ('The quick brown fox', 'QUICK', 'LARGE')
```
The result is the string 'The LARGE brown fox'.