# instrb
**数据库类型与版本**
- 源库类型与版本：Oracle所有版本。
- 目标库类型与版本：GaussDB V2.0-2.7之前版本。
**转换替代方案：**
```
CREATE OR REPLACE FUNCTION dsc_ora_ext.dsc_fn_instrb
/* This function is used to support Oracle INSTRB */
( i_str           IN   TEXT
, i_substr        IN   TEXT
, i_startpos      IN   INTEGER = 1
, i_occurrence    IN   INTEGER = 1 )
RETURN INTEGER
IMMUTABLE
AS
v_instr         INTEGER;
v_instrb        INTEGER;
BEGIN
v_instr := INSTR(i_str, i_substr, i_startpos, i_occurrence);
IF v_instr     <= 0 THEN
v_instrb    := 0;
ELSIF v_instr   = 1 THEN
v_instrb    := 1;
ELSE
v_instrb    := LENGTHB(LEFT(i_str, INSTR(i_str, i_substr, i_startpos, i_occurrence)-1))+1;
END IF;
RETURN v_instrb;
END;
```