LEFT()

All functions > STRING > LEFT()

Returns the first n characters of the string (or the full string when n is greater than its length).

Signatures

Returns: Leading substring

LEFT(string: VARCHAR, n: BIGINT) → VARCHAR

Notes

• Equivalent to SUBSTR(string, 1, n) for non-negative n; see Related functions (SUBSTR)
• For n larger than the string length, the whole string is returned; for n = 0, the result is ''
• If STRING or N is NULL, the result is NULL (use NULL(VARCHAR) / NULL(BIGINT); bare NULL fails inference)

Examples

SELECT
    f1 := LEFT('abcdef', 3), -- First three characters
    f2 := LEFT('abcdef', 3), -- Matches SUBSTR from the start
    f3 := LEFT('hi', 10), -- n longer than string
    f4 := LEFT('x', 0), -- Zero length
    f5 := LEFT(NULL(VARCHAR), 3) -- NULL string yields NULL
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