Question

有没有办法在MySQL数据库的所有表中获取行数而不在每个表上运行SELECT count()？

Answer 1

SELECT SUM(TABLE_ROWS) 
     FROM INFORMATION_SCHEMA.TABLES 
     WHERE TABLE_SCHEMA = '{your_db}';

Note from the docs though:对于InnoDB表，行计数只是SQL优化中使用的粗略估计。您需要使用COUNT（*）来获得准确的计数（这更贵）。

Answer 2

你可以把Tables table放在一起。我从来没有这样做过，但看起来它有 TABLE_ROWS 的列和 TABLE NAME 的列。

要获取每个表的行，您可以使用如下查询：

SELECT table_name, table_rows
FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_SCHEMA = '**YOUR SCHEMA**';

Answer 3

与@Venkatramanan和其他人一样，我发现INFORMATION_SCHEMA.TABLES不可靠（使用InnoDB，MySQL 5.1.44），每次运行时都会提供不同的行数，即使在静默表上也是如此。这是一种相对hacky（但灵活/适应性强）的生成大型SQL语句的方法，您可以将其粘贴到新查询中，而无需安装Ruby gems和东西。

SELECT CONCAT(
    'SELECT "', 
    table_name, 
    '" AS table_name, COUNT(*) AS exact_row_count FROM `', 
    table_schema,
    '`.`',
    table_name, 
    '` UNION '
) 
FROM INFORMATION_SCHEMA.TABLES 
WHERE table_schema = '**my_schema**';

它产生如下输出：

SELECT "func" AS table_name, COUNT(*) AS exact_row_count FROM my_schema.func UNION                         
SELECT "general_log" AS table_name, COUNT(*) AS exact_row_count FROM my_schema.general_log UNION           
SELECT "help_category" AS table_name, COUNT(*) AS exact_row_count FROM my_schema.help_category UNION       
SELECT "help_keyword" AS table_name, COUNT(*) AS exact_row_count FROM my_schema.help_keyword UNION         
SELECT "help_relation" AS table_name, COUNT(*) AS exact_row_count FROM my_schema.help_relation UNION       
SELECT "help_topic" AS table_name, COUNT(*) AS exact_row_count FROM my_schema.help_topic UNION             
SELECT "host" AS table_name, COUNT(*) AS exact_row_count FROM my_schema.host UNION                         
SELECT "ndb_binlog_index" AS table_name, COUNT(*) AS exact_row_count FROM my_schema.ndb_binlog_index UNION

复制并粘贴除最后一个UNION之外的其他输出，以获得良好的输出，如

+------------------+-----------------+
| table_name       | exact_row_count |
+------------------+-----------------+
| func             |               0 |
| general_log      |               0 |
| help_category    |              37 |
| help_keyword     |             450 |
| help_relation    |             990 |
| help_topic       |             504 |
| host             |               0 |
| ndb_binlog_index |               0 |
+------------------+-----------------+
8 rows in set (0.01 sec)

Answer 4

我跑了：

show table status;

这将为您提供每个表的行数以及一堆其他信息。我以前使用上面选择的答案，但这更容易。

我不确定这是否适用于所有版本，但我使用的是InnoDB引擎。

Answer 5

 SELECT TABLE_NAME,SUM(TABLE_ROWS) 
 FROM INFORMATION_SCHEMA.TABLES 
 WHERE TABLE_SCHEMA = 'your_db' 
 GROUP BY TABLE_NAME;

这就是你所需要的一切。

Answer 6

此存储过程列出表，计算记录，并在结尾处生成总记录数。

在添加此程序后运行它：

CALL `COUNT_ALL_RECORDS_BY_TABLE` ();

-

程序：

DELIMITER $$

CREATE DEFINER=`root`@`127.0.0.1` PROCEDURE `COUNT_ALL_RECORDS_BY_TABLE`()
BEGIN
DECLARE done INT DEFAULT 0;
DECLARE TNAME CHAR(255);

DECLARE table_names CURSOR for 
    SELECT table_name FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA = DATABASE();

DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = 1;

OPEN table_names;   

DROP TABLE IF EXISTS TCOUNTS;
CREATE TEMPORARY TABLE TCOUNTS 
  (
    TABLE_NAME CHAR(255),
    RECORD_COUNT INT
  ) ENGINE = MEMORY; 


WHILE done = 0 DO

  FETCH NEXT FROM table_names INTO TNAME;

   IF done = 0 THEN
    SET @SQL_TXT = CONCAT("INSERT INTO TCOUNTS(SELECT '" , TNAME  , "' AS TABLE_NAME, COUNT(*) AS RECORD_COUNT FROM ", TNAME, ")");

    PREPARE stmt_name FROM @SQL_TXT;
    EXECUTE stmt_name;
    DEALLOCATE PREPARE stmt_name;  
  END IF;

END WHILE;

CLOSE table_names;

SELECT * FROM TCOUNTS;

SELECT SUM(RECORD_COUNT) AS TOTAL_DATABASE_RECORD_CT FROM TCOUNTS;

END

Answer 7

你可以试试这个。它对我来说很好。

SELECT IFNULL(table_schema,'Total') "Database",TableCount 
FROM (SELECT COUNT(1) TableCount,table_schema 
      FROM information_schema.tables 
      WHERE table_schema NOT IN ('information_schema','mysql') 
      GROUP BY table_schema WITH ROLLUP) A;

Answer 8

如果使用数据库information_schema，则可以使用此mysql代码（where部分使查询不显示对行具有空值的表）：

SELECT TABLE_NAME, TABLE_ROWS
FROM `TABLES`
WHERE `TABLE_ROWS` >=0

Answer 9

这个估计问题有一些黑客/解决方法。

Auto_Increment - 由于某些原因，如果您在表上设置了自动增量，则会为数据库返回更准确的行数。

在探索为什么show table info与实际数据不匹配时找到了这个。

SELECT
table_schema 'Database',
SUM(data_length + index_length) AS 'DBSize',
SUM(TABLE_ROWS) AS DBRows,
SUM(AUTO_INCREMENT) AS DBAutoIncCount
FROM information_schema.tables
GROUP BY table_schema;


+--------------------+-----------+---------+----------------+
| Database           | DBSize    | DBRows  | DBAutoIncCount |
+--------------------+-----------+---------+----------------+
| Core               |  35241984 |   76057 |           8341 |
| information_schema |    163840 |    NULL |           NULL |
| jspServ            |     49152 |      11 |            856 |
| mysql              |   7069265 |   30023 |              1 |
| net_snmp           |  47415296 |   95123 |            324 |
| performance_schema |         0 | 1395326 |           NULL |
| sys                |     16384 |       6 |           NULL |
| WebCal             |    655360 |    2809 |           NULL |
| WxObs              | 494256128 |  530533 |        3066752 |
+--------------------+-----------+---------+----------------+
9 rows in set (0.40 sec)

然后，您可以轻松使用PHP或其他任何内容返回2个数据列的最大值，以便为行数提供“最佳估计值”。

即。

SELECT
table_schema 'Database',
SUM(data_length + index_length) AS 'DBSize',
GREATEST(SUM(TABLE_ROWS), SUM(AUTO_INCREMENT)) AS DBRows
FROM information_schema.tables
GROUP BY table_schema;

自动增量将始终为+1 *（表计数）行，但即使有4,000个表和300万行，也准确率为99.9％。比估计的行好多了。

这样做的好处是，performance_schema中返回的行计数也会被删除，因为最大值对空值不起作用。如果没有自动增量的表，这可能是一个问题。

Answer 10

以下查询生成（nother）查询，该查询将从information_schema.tables中列出的每个模式获取每个表的count（*）值。这里显示的查询的整个结果 - 所有行一起 - 包含以分号结尾的有效SQL语句 - 没有悬空的“联合”。通过在下面的查询中使用联合来避免悬空联合。

select concat('select "', table_schema, '.', table_name, '" as `schema.table`,
                          count(*)
                 from ', table_schema, '.', table_name, ' union ') as 'Query Row'
  from information_schema.tables
 union
 select '(select null, null limit 0);';

Answer 11

这是我做的实际计数（不使用架构）

它更慢但更准确。

这是

的两个步骤

获取数据库的表列表。你可以使用
获得它
```
mysql -uroot -p mydb -e "show tables"
```
在此bash脚本中创建表格列表并将其分配给数组变量（由单个空格分隔，就像在下面的代码中一样）
```
array=( table1 table2 table3 )

for i in "${array[@]}"
do
    echo $i
    mysql -uroot mydb -e "select count(*) from $i"
done
```
运行它：
```
chmod +x script.sh; ./script.sh
```

Answer 12

还有一个选择：对于非InnoDB，它使用来自information_schema.TABLES的数据（因为它更快），对于InnoDB - 选择count（*）来获得准确的计数。它也忽略了观点。

SET @table_schema = DATABASE();
-- or SET @table_schema = 'my_db_name';

SET GROUP_CONCAT_MAX_LEN=131072;
SET @selects = NULL;

SELECT GROUP_CONCAT(
        'SELECT "', table_name,'" as TABLE_NAME, COUNT(*) as TABLE_ROWS FROM `', table_name, '`'
        SEPARATOR '\nUNION\n') INTO @selects
  FROM information_schema.TABLES
  WHERE TABLE_SCHEMA = @table_schema
        AND ENGINE = 'InnoDB'
        AND TABLE_TYPE = "BASE TABLE";

SELECT CONCAT_WS('\nUNION\n',
  CONCAT('SELECT TABLE_NAME, TABLE_ROWS FROM information_schema.TABLES WHERE TABLE_SCHEMA = ? AND ENGINE <> "InnoDB" AND TABLE_TYPE = "BASE TABLE"'),
  @selects) INTO @selects;

PREPARE stmt FROM @selects;
EXECUTE stmt USING @table_schema;
DEALLOCATE PREPARE stmt;

如果你的数据库有很多大的InnoDB表，那么所有的行都会花费更多的时间。

Answer 13

如果您需要确切的数字，请使用以下ruby脚本。你需要Ruby和RubyGems。

安装以下宝石：

$> gem install dbi
$> gem install dbd-mysql

档案：count_table_records.rb

require 'rubygems'
require 'dbi'

db_handler = DBI.connect('DBI:Mysql:database_name:localhost', 'username', 'password')

# Collect all Tables
sql_1 = db_handler.prepare('SHOW tables;')
sql_1.execute
tables = sql_1.map { |row| row[0]}
sql_1.finish

tables.each do |table_name|
  sql_2 = db_handler.prepare("SELECT count(*) FROM #{table_name};")
  sql_2.execute
  sql_2.each do |row|
    puts "Table #{table_name} has #{row[0]} rows."
  end
  sql_2.finish
end

db_handler.disconnect

返回命令行：

$> ruby count_table_records.rb

输出：

Table users has 7328974 rows.

Answer 14

这就是我使用PHP计算TABLES和ALL RECORDS的方式：

$dtb = mysql_query("SHOW TABLES") or die (mysql_error());
$jmltbl = 0;
$jml_record = 0;
$jml_record = 0;

while ($row = mysql_fetch_array($dtb)) { 
    $sql1 = mysql_query("SELECT * FROM " . $row[0]);            
    $jml_record = mysql_num_rows($sql1);            
    echo "Table: " . $row[0] . ": " . $jml_record record . "<br>";      
    $jmltbl++;
    $jml_record += $jml_record;
}

echo "--------------------------------<br>$jmltbl Tables, $jml_record > records.";

Answer 15

海报想要行计数而不计算，但没有指定哪个表引擎。使用InnoDB，我只知道一种方法，即计算。

这就是我挑选土豆的方法：

# Put this function in your bash and call with:
# rowpicker DBUSER DBPASS DBNAME [TABLEPATTERN]
function rowpicker() {
    UN=$1
    PW=$2
    DB=$3
    if [ ! -z "$4" ]; then
        PAT="LIKE '$4'"
        tot=-2
    else
        PAT=""
        tot=-1
    fi
    for t in `mysql -u "$UN" -p"$PW" "$DB" -e "SHOW TABLES $PAT"`;do
        if [ $tot -lt 0 ]; then
            echo "Skipping $t";
            let "tot += 1";
        else
            c=`mysql -u "$UN" -p"$PW" "$DB" -e "SELECT count(*) FROM $t"`;
            c=`echo $c | cut -d " " -f 2`;
            echo "$t: $c";
            let "tot += c";
        fi;
    done;
    echo "total rows: $tot"
}

除了这是一个非常丑陋但有效的方法来获取数据库中每个表中存在多少行而不管表引擎并且无需安装存储过程的权限之外，我没有对此进行断言。需要安装ruby或php。是的，它生锈了。是的，很重要。 count（*）是准确的。

Answer 16

简单方法：

Traceback (most recent call last):
File "/var/www/html/ftest.py", line 116, in <module>
  mydb,cur=connectdb()
File "/var/www/html/ftest.py", line 55, in connectdb
mx.connect(host='localhost',user='*****',passwd='********',database='searchdb')
File "/usr/lib/python2.7/site-packages/mysql/connector/__init__.py", line 98, in connect
  return MySQLConnection(*args, **kwargs)
File "/usr/lib/python2.7/site-packages/mysql/connector/connection.py", line 118, in __init__
  self.connect(**kwargs)
File "/usr/lib/python2.7/site-packages/mysql/connector/connection.py", line 382, in connect
  self._open_connection()
File "/usr/lib/python2.7/site-packages/mysql/connector/connection.py", line 345, in _open_connection
  self._socket_open_connection()
File "/usr/lib/python2.7/site-packages/mysql/connector/network.py", line 386, in _open_connection
  errno=2003, values=(self.get_address(), _strioerror(err)))
InterfaceError: 2003: Can't connect to MySQL server on 'localhost:3306' (13 Permission denied)

结果示例：

SELECT
  TABLE_NAME, SUM(TABLE_ROWS)
FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_SCHEMA = '{Your_DB}'
GROUP BY TABLE_NAME;

Answer 17

基于上述@Nathan的答案，但无需“删除最终的并集”，并且可以选择对输出进行排序，因此使用以下SQL。它生成另一个SQL语句，然后直接运行：

select CONCAT( 'select * from (\n', group_concat( single_select SEPARATOR ' UNION\n'), '\n ) Q order by Q.exact_row_count desc') as sql_query
from (
    SELECT CONCAT(
        'SELECT "', 
        table_name, 
        '" AS table_name, COUNT(1) AS exact_row_count
        FROM `', 
        table_schema,
        '`.`',
        table_name, 
        '`'
    ) as single_select
    FROM INFORMATION_SCHEMA.TABLES 
    WHERE table_schema = 'YOUR_SCHEMA_NAME'
      and table_type = 'BASE TABLE'
) Q

您确实需要一个足够大的group_concat_max_len服务器变量，但是从MariaDb 10.2.4开始，它应该默认为1M。

Answer 18

下面的代码为所有故事生成选择查询。只需删除最后一个“ UNION ALL”，选择所有结果并粘贴一个新的查询窗口即可运行。

SELECT 
concat('select ''', table_name ,''' as TableName, COUNT(*) as RowCount from ' , table_name , ' UNION ALL ')  as TR FROM
information_schema.tables where 
table_schema = 'Database Name'

Answer 19

如果您知道表的数量及其名称，并假设每个表都有主键，则可以使用交叉连接与COUNT(distinct [column])组合来获取每个表中的行：

SELECT 
   COUNT(distinct t1.id) + 
   COUNT(distinct t2.id) + 
   COUNT(distinct t3.id) AS totalRows
FROM firstTable t1, secondTable t2, thirdTable t3;

以下是SQL Fiddle示例。

获取MySQL数据库中所有表的记录计数

19 个答案: