SUBSTR

Extracts a substring from a string.

This function corresponds to the substr(X, Y, Z) function in SQLite. It returns a substring of the input string from the column, starting at a specified position, with an optional length.

• The start index is 1-based. A positive value indicates the starting position from the beginning of the string.

• A negative start value indicates the starting position from the end of the string. For example, -1 is the last character, -2 is the second to last, and so on.

• If length is provided, it specifies the number of characters to extract. A negative length is not meaningful and may produce undefined results.

• If length is omitted, all characters from the start position to the end of the string are returned.

This function is an alias for SUBSTRING.

Example

// SELECT substr('KQLite is fun', 1, 6) -> 'KQLite'
select(SUBSTR(StringLiteral("KQLite is fun"), 1, 6))

// Get the last 3 characters
// SELECT substr('KQLite is fun', -3) -> 'fun'
select(SUBSTR(StringLiteral("KQLite is fun"), -3))

// Using a column to get a prefix
val userPrefix = select(SUBSTR(Users.username, 1, 3)).from(Users)

Parameters

See also