是否有一种方法可以获得MySQL数据库中所有表的行计数,而无需在每个表上运行SELECT count() ?
当前回答
我不知道为什么这么难,但这就是生活。 下面是执行实际计数的bash脚本。只需将其保存为(例如count_rows.sh),使其可执行(例如chmod 755 count_rows.sh),并运行它(例如。/count_rows.sh)
#!/bin/bash
readarray -t TABLES < <(mysql --skip-column-names -u myuser -pmypassword mydbname -e "show tables")
# now we have an array like:
# TABLES='([0]="customer" [1]="order" [2]="product")'
# You can print out the array with:
#declare -p TABLES
for i in "${TABLES[@]}"
do
#echo $i
COUNT=$(mysql --skip-column-names -u username -pmypassword mydbname -e "select count(*) from $i")
echo $i : $COUNT
done
其他回答
SELECT SUM(TABLE_ROWS)
FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_SCHEMA = '{your_db}';
从文档中注意到:对于InnoDB表,行数只是用于SQL优化的粗略估计。您需要使用COUNT(*)来获得精确的计数(成本更高)。
你可以用表格把一些东西组合在一起。我从来没有这样做过,但它看起来有一个列用于TABLE_ROWS和一个列用于TABLE NAME。
要获取每个表的行,你可以使用这样的查询:
SELECT table_name, table_rows
FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_SCHEMA = '**YOUR SCHEMA**';
像许多其他人一样,我很难用InnoDB在INFORMATION_SCHEMA表上获得准确的值,并且能够通过count()进行查询将无限受益,并且希望在一次查询中完成它。
首先,确保启用大规模group_concats:
SET SESSION group_concat_max_len = 1000000;
然后运行此查询以获得将为数据库运行的结果查询。
SELECT CONCAT('SELECT ', GROUP_CONCAT(table1.count SEPARATOR ',\n')) FROM (
SELECT concat('(SELECT count(id) AS \'',table_name,' Count\' ','FROM ',table_name,') AS ',table_name,'_Count') AS 'count'
FROM information_schema.tables
WHERE table_schema = '**YOUR_DATABASE_HERE**'
) AS table1
这将生成诸如…
SELECT (SELECT count(id) AS 'table1 Count' FROM table1) AS table1_Count,
(SELECT count(id) AS 'table2 Count' FROM table2) AS table2_Count,
(SELECT count(id) AS 'table3 Count' FROM table3) AS table3_Count;
这反过来又产生了以下结果:
*************************** 1. row ***************************
table1_Count: 1
table2_Count: 1
table3_Count: 0
这个存储过程列出表,统计记录,并在最后生成记录的总数。
添加此过程后运行:
CALL `COUNT_ALL_RECORDS_BY_TABLE` ();
-
过程:
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
还有一个选择:对于非InnoDB,它使用information_schema中的数据。TABLES(因为它更快),对于InnoDB -选择count(*)来获得准确的计数。它还会忽略视图。
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,计算所有行会花费更多的时间。
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