MySQL - 如何在一个查询中计算每个表的所有行

Question

有没有办法查询数据库以找出所有表中有多少行？

即

table1 1234
table2 222
table3 7888

希望你能提出建议

Answer 1

SELECT 
    TABLE_NAME, 
    TABLE_ROWS 
FROM 
    `information_schema`.`tables` 
WHERE 
    `table_schema` = 'YOUR_DB_NAME';

Answer 2

将上面的信息和这篇文章合成一组查询，我们得到一个自写查询，它将提供准确的行数：

SET @tableSchema = 'my_schema';
SET SESSION group_concat_max_len = 10000000;
SET @rowCounts = (
  SELECT group_concat(CONCAT('SELECT ''',TABLE_NAME,''', COUNT(*) FROM ', TABLE_NAME) SEPARATOR ' union all ')
  FROM information_schema.tables WHERE table_schema = @tableSchema
);
PREPARE statement FROM @rowCounts;
EXECUTE statement;

-- don't run dealloc until you've exported your results ;)
DEALLOCATE PREPARE statement;

Answer 3

上面将给出一个近似值,但如果你想要一个精确的计数,它可以分两步完成.首先,执行如下查询:

select concat("select '",table_name,"', count(*) from ",table_name,";") 
from `information_schema`.`tables` 
WHERE `table_schema` = '[your schema here]';

这将生成一个SQL语句列表,一个用于数据库中的每个表,然后可以运行以获得精确计数.

Answer 4

这将为您提供确切的表名称和单个列表上的计数

SELECT CONCAT('SELECT ''',table_name,''', COUNT(*) FROM ', table_name, ' union all') 
      FROM information_schema.tables WHERE table_schema = 'clw';

Answer 5

SELECT 
    table_name, 
    table_rows 
FROM 
    INFORMATION_SCHEMA.TABLES