FUNCTION IS_DATE( IN_DATE IN VARCHAR2) RETURN INTEGER AS FLAG INTEGER; YER VARCHAR2(4); MON VARCHAR2(2); TOD VARCHAR2(2); BEGIN IF INSTR(IN_DATE, '-', 1, 1)=0 AND LENGTH(IN_DATE)=8 THEN YER :=SUBSTR(IN_DATE,1,4); MON :=SUBSTR(IN_DATE,5,2); TOD :=SUBSTR(IN_DATE,7,2); ELSE IF INSTR(IN_DATE, '-', 1, 1)=5 AND LENGTH(IN_DATE)=10 THEN YER :=SUBSTR(IN_DATE,1,4); MON :=SUBSTR(IN_DATE,6,2); TOD :=SUBSTR(IN_DATE,9,2); ELSE RETURN -1; END IF; END IF; IF MON NOT IN ('01','02','03','04','05','06','07','08','09','10','11','12') THEN RETURN -2; END IF; IF MON IN ('01','03','05','07','08','10','12') AND (TOD>'31' OR TOD<'01') THEN RETURN -3; END IF; IF MON IN('04','06','09','11') AND (TOD>'30' OR TOD<'01') THEN RETURN -4; END IF; IF MON='02' AND ((MOD(YER,4)=0 AND MOD(YER,100)<>0 OR MOD(YER,400)=0)) AND (TOD>'29' OR TOD<'01') THEN RETURN -5; END IF; IF MON='02' AND ( TOD>'28' OR TOD<'01') THEN RETURN -6; END IF; RETURN 0; END IS_DATE
|