Question

说我有一个带有文本数组参数TEXT []的函数。如果执行EXECUTE FORMAT INSERT，如何传递该数组的带引号的文本字符串以插入？

Answer 1

您应该使用USING子句。动态SQL可以在通常的地方使用参数（非SQL标识符）：

CREATE TABLE foo(a varchar[]);

CREATE OR REPLACE FUNCTION public.fx(tblname text, VARIADIC p character varying[])
RETURNS void LANGUAGE plpgsql AS $function$
BEGIN
  EXECUTE format('insert into %I(a) VALUES($1)', tblname) USING p;
END;
$function$

SELECT fx('foo', 'Hi','Hello');
SELECT fx('foo', 'Hi','Hel''lo');
SELECT fx('foo', 'Hi','Hel"lo');

postgres=# SELECT * FROM foo;
┌────────────────┐
│       a        │
╞════════════════╡
│ {Hi,Hel'lo}    │
│ {Hi,"Hel\"lo"} │
│ {Hi,Hello}     │
└────────────────┘
(3 rows)

Answer 2

谢谢，我现在知道何时使用using和格式。这是我修改后的代码：

CREATE OR REPLACE FUNCTION add_property(catid INT, colname TEXT,
ty catalog_column_type, colval TEXT[])

RETURNS jsonb AS $$

DECLARE

    tn TEXT;

BEGIN

--check table exists

SELECT tablename INTO tn FROM catalog WHERE catalogid=catid;

IF NOT EXISTS(SELECT 1 FROM information_schema.tables WHERE table_name=tn)
    THEN
    return jsonb_build_object('error','notable');

END IF;

--check if property exists for table

IF EXISTS(SELECT 1 FROM catalog_columns WHERE catalogid=catid AND
    columnname=colname) THEN
    return jsonb_build_object('error','exists');

END IF;

IF ty='INT'::catalog_column_type THEN
    EXECUTE FORMAT ('ALTER TABLE %I ADD COLUMN %I INT',tn,colname);

ELSIF ty='TEXT'::catalog_column_type THEN
    EXECUTE FORMAT ('ALTER TABLE %I ADD COLUMN %I TEXT',tn,colname);

ELSIF ty='ENUM'::catalog_column_type THEN
    EXECUTE FORMAT ('ALTER TABLE %I ADD COLUMN %I INT',tn,colname);

ELSIF ty='BOOLEAN'::catalog_column_type THEN
    EXECUTE FORMAT ('ALTER TABLE %I ADD COLUMN %I BOOLEAN',tn,colname);

END IF;


    EXECUTE 'INSERT INTO catalog_columns (catalogid,columnname,'
    || 'columntype,columnnvalues) VALUES ($1,$2,$3,$4)' USING catid,colname,

        ty,colval;

return jsonb_build_object('error','OK');

END;
$$ LANGUAGE plpgsql;

Pl / Pgsql，将数组参数传递给INSERT

2 个答案: