使用SQL Server从每个表和每个列中获取不同的值 [英] Get distinct values from each table and each column with SQL Server

问题描述

我想遍历给定数据库的每个表，以获得每个char字段的唯一值。

I would like to loop through each table for a given database to get unique values for each char field.

我的查询可能类似于：

for each table:
    for each row in table:
       select distinct char_field
       from table
    loop
loop

我该怎么做？

推荐答案

像这样尝试

DECLARE cur CURSOR FOR
    SELECT 'SELECT DISTINCT ' + QUOTENAME(c.COLUMN_NAME) + 'AS ' + QUOTENAME(TABLE_CATALOG + '.' + TABLE_SCHEMA + '.' + TABLE_NAME) + ' FROM ' + QUOTENAME(TABLE_CATALOG) + '.' + QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME)
    FROM INFORMATION_SCHEMA.COLUMNS AS c
    WHERE c.DATA_TYPE LIKE '%char%' 

DECLARE @cmd VARCHAR(MAX);
OPEN cur;

FETCH NEXT FROM cur INTO @cmd;
WHILE @@FETCH_STATUS = 0
BEGIN
    PRINT @cmd
    EXEC(@cmd);
    FETCH NEXT FROM cur INTO @cmd;
END

CLOSE cur;
DEALLOCATE cur;

此过程将打开一个游标，其中包含所有表的所有列，其中数据类型包含 char 。它将创建一条语句以选择所有不同的值，然后一个接一个地执行。

This process opens a cursor with all columns of all tables, where the data-type contains char. It will create a statement to select all distinct values and executes this one after the other.

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