SQL语句求助！红色标出的语句提示语法错误！这段代码的目的是“实现创建用户名，密码和权限，要求用户名不能重复”

[hunaijiao]

string ls_yonghu,ls_mima,ls_queren,ls_quanxian
ls_yonghu=trim(sle_1.text)
ls_mima=trim(sle_2.text)
ls_queren=trim(sle_3.text)
ls_quanxian=trim(ddlb_1.text)

if ls_yonghu="" or ls_mima="" or ls_queren="" or ls_quanxian="" then
messagebox("提示!","各项信息不能为空!")
else
if ls_mima=ls_queren then
if not exists(select yonghu from zhanghao where yonghu=:ls_yonghu) then
insert into zhanghao(yonghu,mima,quanxian)values(:ls_yonghu,:ls_mima,:ls_quanxian);
if sqlca.sqlcode=0 then
commit using SQLCA;
messagebox("成功!","用户创建成功!")
ddlb_1.SelectItem(0)
sle_2.text=""
sle_3.text=""
sle_1.text=""
else
messagebox("失败!","用户创建失败!")
rollback;
ddlb_1.SelectItem(0)
sle_2.text=""
sle_3.text=""
sle_1.text=""
end if
else
messagebox("提示!","该用户名已存在!")
end if
else
messagebox("提示!","密码确认错误!")
sle_2.text=""
sle_3.text=""
end if
end if

[wag_enu]

嵌入式SQL 没有 exists 方法。因而提示错误。
可以改成：
int li_count
select count(1) into :li_count from zhanghao where yonghu=:ls_yonghu

if li_count > 0 then
insert .....

[a954105626]

楼上整洁

[网络橘子]

1楼正解

[zhy686]

楼主估计之前接触的数据是SQLserver.