begin if a>0 then null; --your statement else null; --your statement end if; end;
我說的是在SQl 語句裡怎麼用IF語句
上面的語句的確可以在oracle使用,PL/SQL語言create or replace function sign_num(x in number) return number is z number; begin if X>0 then Z:=1; else Z:=-1; return Z; end;
CASE WHEN 例子 SELECT "ZZJG_RY"."DWBM", CASE WHEN to_number( substr( "ZGXX"."WHCD",1,1) )>=7 THEN '6' ELSE substr( "ZGXX"."WHCD",1,1) END FROM "ZGXX", "ZZJG_RY" WHERE ( zgxx.zgdm = zzjg_ry.zgdm (+)) and ( ( "ZGXX"."ZGZT" = '0' ) )
不知道你要求的功能能不能用decode函数实现? decode(strings,str1,value1,str2,value2,....); 含义是if strings = str1 then 函数返回value1; if strings = str2 then 函数返回value2; ...
if a>0 then
null; --your statement
else
null; --your statement
end if;
end;
return number is
z number;
begin
if X>0 then
Z:=1;
else
Z:=-1;
return Z;
end;
例子 SELECT "ZZJG_RY"."DWBM",
CASE WHEN to_number( substr( "ZGXX"."WHCD",1,1) )>=7 THEN '6' ELSE substr( "ZGXX"."WHCD",1,1) END
FROM "ZGXX",
"ZZJG_RY"
WHERE ( zgxx.zgdm = zzjg_ry.zgdm (+)) and
( ( "ZGXX"."ZGZT" = '0' ) )
decode(strings,str1,value1,str2,value2,....);
含义是if strings = str1 then 函数返回value1;
if strings = str2 then 函数返回value2;
...