函数中的Postgres语法错误 [英] Postgres syntax error in a function

问题描述

我正在尝试创建一个函数，但在以下代码中找不到我的错误:

I am trying to create a function and I can't find my error in the following code:

CREATE OR REPLACE FUNCTION qwat_od.fn_label_create_fields(table_name varchar, position boolean = true, rotation boolean = true) RETURNS void AS
$BODY$
    BEGIN
        /* Creates columns */
        EXECUTE 'ALTER TABLE qwat_od.'||table_name||' ADD COLUMN label_1_visible  smallint default 1;           ';
        IF position IS TRUE THEN
            EXECUTE 'ALTER TABLE qwat_od.'||table_name||' ADD COLUMN label_1_x        double precision default null;';
            EXECUTE 'ALTER TABLE qwat_od.'||table_name||' ADD COLUMN label_1_y        double precision default null;';
        END IF;
        IF rotation IS TRUE THEN
            EXECUTE 'ALTER TABLE qwat_od.'||table_name||' ADD COLUMN label_1_rotation double precision default null;';
        END IF;
        EXECUTE 'ALTER TABLE qwat_od.'||table_name||' ADD COLUMN label_1_text     varchar(120);';

        EXECUTE 'ALTER TABLE qwat_od.'||table_name||' ADD COLUMN label_2_visible  smallint default 1;           ';
        IF position IS TRUE THEN
            EXECUTE 'ALTER TABLE qwat_od.'||table_name||' ADD COLUMN label_2_x        double precision default null;';
            EXECUTE 'ALTER TABLE qwat_od.'||table_name||' ADD COLUMN label_2_y        double precision default null;';
        END IF;
        IF rotation IS TRUE THEN
            EXECUTE 'ALTER TABLE qwat_od.'||table_name||' ADD COLUMN label_2_rotation double precision default null;';
        END IF;

        EXECUTE 'ALTER TABLE qwat_od.'||table_name||' ADD COLUMN label_2_text     varchar(120);';
        /* Creates constraints */
        EXECUTE 'ALTER TABLE qwat_od.'||table_name||' ADD CONSTRAINT '||table_name||'_label_1_visible FOREIGN KEY (label_1_visible) REFERENCES qwat_vl.visible(vl_code_int) MATCH FULL; CREATE INDEX fki_'||table_name||'_label_1_visible  ON qwat_od.'||table_name||'(label_1_visible);';
        EXECUTE 'ALTER TABLE qwat_od.'||table_name||' ADD CONSTRAINT '||table_name||'_label_2_visible FOREIGN KEY (label_2_visible) REFERENCES qwat_vl.visible(vl_code_int) MATCH FULL; CREATE INDEX fki_'||table_name||'_label_2_visible  ON qwat_od.'||table_name||'(label_2_visible);';
    END;
$BODY$
LANGUAGE 'plpgsql';

我明白了:

ERROR:  syntax error at or near "position"
LINE 4: ...wat_od.fn_label_create_fields(table_name varchar, position b...

我在参数声明中做错了吗?

Did I do something wrong in the declaration of arguments?

推荐答案

@ pozs已经为您看到的错误提供了一个解释.
但是还有更多.最重要的是，您可以公开使用 SQL注入 .

@pozs already provided an explanation for the error you saw.
But there is more. Most importantly, you are wide open to SQL injection.

CREATE OR REPLACE FUNCTION qwat_od.fn_label_create_fields(_tbl text, _position bool = true, _rotation bool = true)
  RETURNS void AS
$func$
BEGIN
    /* Creates columns */
   EXECUTE format('ALTER TABLE qwat_od.%I ADD COLUMN label_1_visible smallint default 1', _tbl);

   IF _position THEN
       EXECUTE format('ALTER TABLE qwat_od.%I
           ADD COLUMN label_1_x double precision default null
         , ADD COLUMN label_1_y double precision default null', _tbl);
   END IF;
   IF _rotation THEN
       EXECUTE format('ALTER TABLE qwat_od.%I ADD COLUMN label_1_rotation double precision default null' , _tbl);
   END IF;

   EXECUTE format('ALTER TABLE qwat_od.%I
           ADD COLUMN label_1_text varchar(120)    
         , ADD COLUMN label_2_visible  smallint default 1', _tbl);

   IF _position THEN
       EXECUTE format('ALTER TABLE qwat_od.%I
           ADD COLUMN label_2_x double precision default null
         , ADD COLUMN label_2_y double precision default null', _tbl);
   END IF;
   IF _rotation THEN
       EXECUTE format('ALTER TABLE qwat_od.%I ADD COLUMN label_2_rotation double precision default null', _tbl);
   END IF;

   EXECUTE format('ALTER TABLE qwat_od.%I ADD COLUMN label_2_text varchar(120)', _tbl);

   /* Creates constraints */
   EXECUTE format('ALTER TABLE qwat_od.%$1I
           ADD CONSTRAINT %$2I FOREIGN KEY (label_1_visible) REFERENCES qwat_vl.visible(vl_code_int)
         , ADD CONSTRAINT %$3I FOREIGN KEY (label_2_visible) REFERENCES qwat_vl.visible(vl_code_int);
     CREATE INDEX %$4I ON qwat_od.%$1I(label_1_visible);
     CREATE INDEX %$5I ON qwat_od.%$1I(label_2_visible)'
   , _tbl
   , _tbl || '_label_1_visible'
   , _tbl || '_label_2_visible'
   , 'fki_' || _tbl || '_label_1_visible'
   , 'fki_' || _tbl || '_label_2_visible');
END
$func$ LANGUAGE plpgsql;

• 确保使用明确，有效的参数名称(position是 保留字 是主要错误).

  • Be sure to use unambiguous, valid parameter names (position being a reserved word was the primary error).

    我修复了format()的SQL注入问题(因为使用regclass的简单解决方案并未涵盖您的并置名称，如@pozs所述).详细说明:

    I fixed your SQL injection issues with format() (since the simple solution with regclass didn't cover your concatenated names, as commented by @pozs). Detailed explanation:

    • 在触发函数中插入具有动态表名称的
    • 表名作为PostgreSQL函数参数
    • INSERT with dynamic table name in trigger function
    • Table name as a PostgreSQL function parameter

    _tbl必须是不合格的表名("tbl"，而不是"schema.tbl").

    _tbl has to be the unqualified table name ("tbl", not "schema.tbl").

    不引用语言名称，它是一个标识符:LANGUAGE plpgsql

    Don't quote the language name, it's an identifier: LANGUAGE plpgsql

    在单个 ALTER TABLE 语句.

    It's cheaper to add multiple columns / sonstraints in a single ALTER TABLE statement.

    其他各种简化/优化.

    这篇关于函数中的Postgres语法错误的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！