LPAD()

Available in: DSQL, PSQL

Added in: 2.1

Changed in: 2.5 (backported to 2.1.4)

Description: Left-pads a string with spaces or with a user-supplied string until a given length is reached.

Result type: VARCHAR or BLOB

Syntax:

LPAD (str, endlen [, padstr])
This function fully supports text BLOBs of any length and character set.

If str is a BLOB, the result is a BLOB. Otherwise, the result is a VARCHAR(endlen).

If padstr is given and equals '' (empty string), no padding takes place.

If endlen is less than the current string length, the string is truncated to endlen, even if padstr is the empty string.

Important

If the external function LPAD is declared in your database, it will override the internal function. To make the internal function available, DROP or ALTER the external function (UDF).

Note

In Firebird 2.1–2.1.3, all non-BLOB results were of type VARCHAR(32765), which made it advisable to cast them to a more modest size. This is no longer the case.

Examples:

lpad ('Hello', 12)                 -- returns '       Hello'
lpad ('Hello', 12, '-')            -- returns '-------Hello'
lpad ('Hello', 12, '')             -- returns 'Hello'
lpad ('Hello', 12, 'abc')          -- returns 'abcabcaHello'
lpad ('Hello', 12, 'abcdefghij')   -- returns 'abcdefgHello'
lpad ('Hello', 2)                  -- returns 'He'
lpad ('Hello', 2, '-')             -- returns 'He'
lpad ('Hello', 2, '')              -- returns 'He'

Warning

When used on a BLOB, this function may need to load the entire object into memory. Although it does try to limit memory consumption, this may affect performance if huge BLOBs are involved.