Function sqlSubstring

sqlSubstring(
    dialect: Dialect,
    expr: StringSqlExpr,
    start: number,
    length?: number,
): LiteralExpression & { $literal: string }
Extract a substring.
- Oracle, DB2, SQLite: use SUBSTR(expr, start, length). SQLite has no built-in SUBSTRING function (only substr); Oracle/DB2 use SUBSTR as their canonical name (both also happen to accept the same argument order as the standard SUBSTRING(expr, start, length) form).
- MSSQL: SUBSTRING(expr, start, length), but MSSQL requires the length argument. When length is omitted, LEN(expr) is used as a safe upper bound so the result runs to the end of the string.
- MySQL, MariaDB, Postgres, CockroachDB, Redshift, Snowflake, ClickHouse: SUBSTRING(expr, start, length) comma-argument form, length optional.
Parameters
- dialect: Dialect
- expr: StringSqlExpr
  The column/expression to extract from.
- start: number
  1-based start position (SQL substring indices are 1-based).
- Optionallength: number
  Optional number of characters to extract.
Returns LiteralExpression & { $literal: string }
- Defined in query-builders/functions/string.ts:178