pgsql（postgres）中的光标

Question

我再次呼吁您的帮助。我正在将进程从 Oracle 迁移到 postgres。

我声明这个游标来提取信息并将其插入到表中：

esi_cur_fono cursor 
for SELECT (select nextval('edef_seq_pr')) seq_nextval,
        c_pcodigo_soc_dest,
        c_ctac_correlativo,
        c_transac,

        c_transac||
        lpad(c_tr_count, v_transaction_seq,'0')||
        lpad(c_rc_count, v_record_seq,'0')||
        rpad(esi.pers_codigo, v_exploitation_source_id,' ')||
        rpad(translate(esi.nombre,c_cad_n,c_cad_y), v_exploitation_source_name,' ')||
        rpad(esi.esty, v_exploitation_source_type,' ')||
        lpad(c_tisn_cd, v_exploitation_territory_code,'0')||
        lpad(c_tisn_fd, v_exploitation_territory_cvfd,'0')||
        rpad(c_tisan, v_exploitation_territory_abbn,' ')||
        lpad(c_tisn_fd, v_exploitation_territory_avfd,'0'),

        now() fecha,
        tipo_dist,
        (SELECT currval('edef_seq_pr')) edef_padre,
        c_edef_order, 
        NULL, 
        NULL, 
        NULL, 
        NULL, 
        NULL, 
        NULL, 
        NULL, 
        NULL
FROM (SELECT DISTINCT liprt.pers_codigo,
                      pers.pers_nombre_completo nombre,
                      '10' esty,
                      'MEC' tipo_dist
      FROM mocct a 
           INNER JOIN reort b ON a.reor_correlativo = b.reor_correlativo
           INNER JOIN deret c ON c.dere_correlativo = b.dere_correlativo
           INNER JOIN dblink('dbname = crd host=100.1.1.138 port=5432', 'select delp_correlativo, lipr_correlativo from fon_detalles_liq_productor') as delpt (delp_correlativo numeric, lipr_correlativo numeric) ON delpt.delp_correlativo = c.delp_correlativo
           INNER JOIN dblink('dbname = crd host=100.1.1.138 port=5432', 'select lipr_correlativo, pers_codigo from fon_liquidaciones_productor') as liprt (lipr_correlativo numeric, pers_codigo varchar) ON liprt.lipr_correlativo = delpt.lipr_correlativo
           INNER JOIN dblink('dbname = usuarios host=100.1.1.138 port=5432', 'select pers_codigo, pers_nombre_completo from unv_personas') as pers (pers_codigo varchar, pers_nombre_completo varchar) ON liprt.pers_codigo = pers.pers_codigo
      WHERE   a.mocc_monto != 0
      AND b.pers_codigo_socadm = '312951160'
      AND a.ctac_correlativo = 7344) esi;

问题出现在保存游标返回值的变量的声明中，因为不是表，而是子查询，我得到一个错误，所以我求助于声明变量的类型和每个长度的最大值。

/*declaration of cursor variables*/
v_seq_nextval numeric(10);
v_c_pcodigo_soc_dest varchar(10);
v_c_ctac_correlativo varchar(10);
v_c_transac varchar(10);
v_registro varchar(218);
v_fecha date;
v_tipo_dist varchar(10);
v_edef_padre numeric(10);
v_c_edef_order numeric(1);
v_null_1 varchar(10);
v_null_2 varchar(10);
v_null_3 varchar(10);
v_null_4 varchar(10);
v_null_5 varchar(10);
v_null_6 varchar(10);
v_null_7 varchar(10);
v_null_8 varchar(10);

当我执行它时，它给了我以下错误

ERROR:  Missing "FROM or IN" at the end of the SQL expression
LINE 107:    FETCH esi_cursor_fono INTO v_seq_nextval;
                                                 ^
SQL state: 42601
Character: 4897

到处看看，所有的例子都是关于表的，甚至我已经有 2 个可以正常工作，但这是因为查询是直接针对表的，而不是针对子查询的。

Answer 1

不确定您在 FOR 循环中做了什么，但这里有一个示例，您可以使用并适应您的需求：

CREATE OR REPLACE FUNCTION DCPViews.SP_DCPDeleteSchool (
    pSchoolId INTEGER
) 
RETURNS VOID AS $$
DECLARE 
    myclass RECORD;
BEGIN   
    -- Cascaded DELETEs (must delete from child tables first)
    -- Delete all classes associated with school
    FOR myclass IN 
        SELECT ClassId FROM DCP.Class WHERE SchoolId = pSchoolId
    LOOP
        PERFORM DCPViews.SP_DCPDeleteClass(myclass.ClassId); -- PERFORM runs function and discards the results
    END LOOP;

    -- Delete school
    DELETE FROM DCP.School WHERE SchoolId = pSchoolId;

-- Ignore foreign key violation errors
EXCEPTION WHEN foreign_key_violation THEN NULL;
END;
$$ LANGUAGE 'plpgsql';

您不需要将值存储到变量中，只需创建一个新的RECORD 变量，该变量在处理FOR 循环SELECT 语句时存储每个当前行。

如果这是您要查找的内容，或者我是否误读了您的问题，请告诉我。