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SUBSTRING (ODBC compatible)
Syntax
SUBSTRING (ODBC compatible)
Returns the substring of the character string corresponding to the first argument starting at
start_pos and length characters long. If the third argument length is not specified, the
substring starting at start_pos up to the end of char_expression is returned.
SUBSTRING ( char_expression, start_pos [ , length ] )
Example This example illustrates the SUBSTRING function:
SELECT last_name, '(', SUBSTRING (phone, 1, 3) , ')',
SUBSTRING (phone, 4, 3), '-',
SUBSTRING (phone, 7, 4)
FROM customer ;
Notes • The first argument must be of type CHARACTER. It can be any meaningful character value
(for example, a literal expression, database column, or parameter).
• The second argument must be of type INTEGER. It indicates the starting position from
which the substring result is extracted.
• The third argument, if specified, must be of type INTEGER. It indicates the number of
characters the substring function will extract.
• The values for specifying position in the character string start from 1. The first character
in a string is at position 1, the second character is at position 2, and so on.
• The result is of type CHARACTER.
• If any of the argument expressions evaluate to NULL, the result is NULL.
• char_expression and the result can contain multi-byte characters.
• If the value of start_pos is:
– Smaller than 0, the function returns a “Bad argument” error
– Bigger than the actual length of the string value, the function returns an empty zero
length substring
• If the value of length is:
– Smaller than 0, the function returns a “Bad argument” error.
– Bigger than the actual length of the substring (from start_pos to the end of the
literal), the function returns the substring from start_pos to the end of the literal.
– Bigger than the actual length of the substring (from start_pos up to the end of the
column’s row data), the function returns the substring from the start_pos to the end
of the column’s row data. The function returns this, even when the substring result
exceeds the column’s SQL width.
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