ISPREFIXOF

Checks if one string is a prefix of the other.

This is a more peformant way to write y LIKE (x || '%')

See also: LIKE.

Syntax

ISPREFIXOF(needle_string_expr , haystack_string_expr) --> BOOL

Arguments

Parameter Description
needle_string_expr String to locate
haystack_string_expr String to search within

Returns

TRUE if needle_string_expr is a prefix of haystack_string_expr, or FALSE otherwise.

Notes

  • This function is supported on NVARCHAR strings only.
  • If the value is NULL, the result is NULL.

Examples

For these examples, consider the following table and contents:

CREATE TABLE jabberwocky(line VARCHAR(50));

INSERT INTO jabberwocky VALUES
   ('''Twas brillig, and the slithy toves '), ('      Did gyre and gimble in the wabe: ')
   ,('All mimsy were the borogoves, '), ('      And the mome raths outgrabe. ')
   ,('"Beware the Jabberwock, my son! '), ('      The jaws that bite, the claws that catch! ')
   ,('Beware the Jubjub bird, and shun '), ('      The frumious Bandersnatch!" ');

Filtering using ISPREFIXOF

t=> SELECT line FROM jabberwocky WHERE ISPREFIXOF('And',TRIM(line));
line
-----------------------------------
   And the mome raths outgrabe.

Tip

Use TRIM to avoid leading and trailing whitespace issues