Question

我需要对Netezza系统进行行计数，但只有2列具有特定值

我有

SELECT TABLENAME, RELTUPLES 
FROM _V_TABLE 
WHERE objtype = 'TABLE' and tablename like 'MY%STUFF'

这将显示所有表名及其行数

但是我需要在其中添加一个where子句。 columnA = 1，columnB = ABC，

每个表都包含这两个列名。

由于

克雷格

Answer 1

如果要通过SQL执行此操作，则可以使用存储过程完成此操作。这是一个存储过程，可以执行我认为您要求的操作。

我的假设是您只想计算实际匹配指定列值的表中的行，因此_v_tables中的RELTUPLES不会用于此。示例存储过程代码还假定每个列都是varchar（1000）。如果要匹配其他数据类型，则必须更改代码。

在创建存储过程之前，创建一个如下所示的引用表：

create table reftable_sp_row_count (tablename varchar(1000), rowcount bigint) distribute on random;

然后像这样创建存储过程：

CREATE OR REPLACE PROCEDURE SP_ROW_COUNT(VARCHAR(254), VARCHAR(254), VARCHAR(254), VARCHAR(254), VARCHAR(254))
RETURNS REFTABLE(REFTABLE_SP_ROW_COUNT)
EXECUTE AS OWNER
LANGUAGE NZPLSQL AS
BEGIN_PROC
DECLARE
    pTablePattern ALIAS FOR $1;
    pColOneName ALIAS FOR $2;
    pColOneValue ALIAS FOR $3;
    pColTwoName ALIAS FOR $4;
    pcolTwoValue ALIAS FOR $5;

    vRecord RECORD;
BEGIN

for vRecord in 
EXECUTE 'SELECT schema
      || ''.''
      || tablename tablename
FROM _v_table v
WHERE tablename LIKE ''' || upper(pTablePattern) || '''
AND EXISTS
   (
      SELECT attname
      FROM _v_relation_column c
      WHERE c.objid = v.objid
      AND attname   = ''' || upper(pColOneName) || '''
   )
AND EXISTS
   (
      SELECT attname
      FROM _v_relation_column c
      WHERE c.objid = v.objid
      AND attname   = ''' || upper(pColTwoName) || '''
   )'
   LOOP

   EXECUTE IMMEDIATE 'INSERT INTO ' || REFTABLENAME || 
   ' SELECT '''  ||  vRecord.tablename || ''' , COUNT(1) from ' || vRecord.tablename || 
   ' where ' || upper(pColOneName) || ' = ''' || pColOneValue || ''' and ' || upper(pColTwoName) || ' = ''' || pColTwoValue || ''' ;';

   -- Note that if you change the data types for a given column to a different type then you'll want to change ''' || pColOneValue || ''' to ' || pColOneValue || '  as appropriate
   END LOOP;

RETURN REFTABLE;
END;
END_PROC;

以下是一些示例输出。

TESTDB.ADMIN(ADMIN)=> select * from table_1 order by colA, colB;
 COLA | COLB
------+------
 ABC  | BLUE
 ABC  | BLUE
 ABC  | BLUE
 ABC  | RED
 ABC  | RED
(5 rows)

TESTDB.ADMIN(ADMIN)=> select * from table_2 order by colA, colB;
 COLA |  COLB
------+--------
 ABC  | BLUE
 ABC  | BLUE
 XYZ  | BLUE
 XYZ  | BLUE
 XYZ  | YELLOW
(5 rows)

TESTDB.ADMIN(ADMIN)=> call sp_row_count('TABLE_%', 'COLA', 'ABC', 'COLB','BLUE');
   TABLENAME   | ROWCOUNT
---------------+----------
 ADMIN.TABLE_1 |        3
 ADMIN.TABLE_2 |        2
(2 rows)

在DB中列= 1和列= DEV的所有表中进行行计数

1 个答案: