在 mysql "error in your SQL syntax" 上声明游标错误

Question

请帮忙

delimiter $
create procedure corrige_preg()
begin
    declare var_test integer;
    declare var_contador integer;
    set var_contador = 1;
    select test_tnum into var_test from preg
    group by test_tnum having max(pnum)<>count(pnum);
    if var_test is null then
        select "ok";
    else
        declare var_cursor cursor for
        select pnum from preg where test_tnum = var_test;
        open var_cursor;
        loop1: loop
            fetch var_cursor into pnum;
            pnum = var_contador;
            set var_contador=var_contador+1;
        end loop loop1;
        close var_cursor;
    end if;
end $

Error : You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'declare var_cursor cursor for select pnum from preg where test_tnum = var_test' at line 11

Answer 1

将游标声明移到顶部，紧跟在变量声明之后。

例如：

delimiter $
create procedure corrige_preg()
begin
    declare var_test integer;
    declare var_contador integer;
    declare var_pnum integer;

    declare var_cursor cursor for
    select pnum from preg where test_tnum = var_test;   

    set var_contador = 1;
    select test_tnum into var_test from preg
    group by test_tnum having max(pnum)<>count(pnum);
    if var_test is null then
        select "ok";
    else        
        open var_cursor;
        loop1: loop
            fetch var_cursor into var_pnum;
            -- var_pnum = var_contador;
            set var_contador=var_contador+1;
        end loop loop1;
        close var_cursor;
    end if;
end $

Answer 2

声明必须在 BEGIN 之后，因此在 ELSE 块周围包裹一个 BEGIN/END 块。您还需要 pnum 的声明，并且必须使用 SET 语句来分配给它。

delimiter $
create procedure corrige_preg()
begin
    declare var_test integer;
    declare var_contador integer;
    set var_contador = 1;
    select test_tnum into var_test from preg
    group by test_tnum having max(pnum)<>count(pnum);
    if var_test is null then
        select "ok";
    else begin
        declare pnum integer;
        declare var_cursor cursor for
        select pnum from preg where test_tnum = var_test;
        open var_cursor;
        loop1: loop
            fetch var_cursor into pnum;
            set pnum = var_contador;
            set var_contador=var_contador+1;
        end loop loop1;
        close var_cursor;
    end;
    end if;
end $
delimiter ;

在 mysql "error in your SQL syntax" 上声明游标错误

declare cursor error on mysql "error in your SQL syntax"

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