8种数据库获取表行数的方法

1. Oracle数据库:

SELECT
    x.table_name AS 表名,
    x.表行数,
    x.表列数,
    y.表大小 AS 表大小单位MB 
FROM
    (
    SELECT
        b.table_name,
        a.num_rows AS 表行数,
        b.count1 AS 表列数 
    FROM
        user_tables a
        INNER JOIN ( SELECT table_name, count( column_name ) AS count1 FROM user_tab_columns GROUP BY table_name ) b ON a.table_name = b.table_name 
    ORDER BY
        b.table_name 
    ) x LEFT outer
    JOIN (
    SELECT
        sum( tablesize ) AS 表大小,
        tablename 
    FROM
        (
        SELECT
            sum( C.bytes ) / 1024 / 1024 AS tablesize,
            C.table_name AS tablename 
        FROM
            ( SELECT A.table_name, B.bytes FROM user_lobs A, user_extents B WHERE A.segment_name = B.segment_name ) C 
        GROUP BY
            C.table_name UNION ALL
        SELECT
            sum( bytes ) / 1024 / 1024 AS tablesize,
            segment_name AS tablename 
        FROM
            user_extents 
        WHERE
            segment_type = 'TABLE' 
        GROUP BY
            segment_name 
        ) 
    GROUP BY
        tablename 
    ORDER BY
        1 DESC 
    ) y ON x.table_name = y.tablename 
ORDER BY
    y.表大小 desc

2. 神通数据库:

CREATE TABLE table_num (
  table_name VARCHAR2(255),
  table_num NUMBER
);

CREATE OR REPLACE PROCEDURE insert_table_num IS
BEGIN
  FOR t IN (SELECT table_name FROM user_tables) LOOP
  BEGIN
    EXECUTE IMMEDIATE 'INSERT INTO table_num (table_name, table_num)
                      SELECT ''' || t.table_name || ''', COUNT(*) FROM ' || t.table_name;
   EXCEPTION
       when others then 
       null ;
   END;
  END LOOP;
END;

exec insert_table_num;

SELECT * FROM table_num ORDER BY table_num DESC 

3. 达梦数据库

SELECT T.TABLESPACE_NAME,
       T.OWNER,
       T.TABLE_NAME,
       TABLE_ROWCOUNT(T.OWNER, T.TABLE_NAME)                            AS TABLE_ROWCOUNT
FROM DBA_TABLES T
WHERE T.OWNER IN ('YourSchemas_name****') order by TABLE_ROWCOUNT desc

4. MySQL数据库

SELECT
	table_name,
	table_rows 
FROM
	information_schema.TABLES 
WHERE
	table_schema = 'YourSchemas_name' 
ORDER BY
	table_rows DESC

5. PG数据库

SELECT
    relname,
    reltuples
FROM
    pg_class
    CLS LEFT JOIN pg_namespace N ON ( N.oid = CLS.relnamespace )
WHERE
    nspname NOT IN ( 'pg_catalog', 'information_schema' )
    AND relkind = 'r' 
ORDER BY
reltuples DESC;

6. SQLSERVER数据库

SELECT 
    t.name AS TableName,
    SUM(p.rows) AS RowCounts
FROM 
    sys.tables t
INNER JOIN 
    sys.partitions p ON t.object_id = p.object_id
WHERE 
    t.is_ms_shipped = 0
    AND p.index_id IN (0,1)
GROUP BY 
    t.name
ORDER BY 
    RowCounts DESC;

7. 人大金仓数据库-瀚高数据库 应该都可以使用PG的语法

SELECT
    relname,
    reltuples
FROM
    pg_class
    CLS LEFT JOIN pg_namespace N ON ( N.oid = CLS.relnamespace )
WHERE
    nspname NOT IN ( 'pg_catalog', 'information_schema' )
    AND relkind = 'r' 
ORDER BY
reltuples DESC;