mysql 库表整体相关查询

Posted 2022-06-28 sfth

select table_schema,table_name from information_schema.columns where column_name = '字段名';

• 查询某张表有几条记录

select count(*) FROM gasmis_shangxian.his_fuel_record;

• 查询某几张表一个有多少条记录

SELECT SUM(a) from(SELECT COUNT(*) a FROM gasmis_shangxian.his_fuel_record
UNION
SELECT COUNT(*)a FROM gasmis_shangxian.his_account_journal
UNION
SELECT COUNT(*) a FROM gasmis_shangxian.his_oilsys_fuel_record) as aa

• 查询某个字段属于哪个库

- > select table_schema,table_name from information_schema.columns where column_name = '字段名'

• 批量更新某个主键，使其值增1，直接update会主键冲突,使用order by (神奇的order by 用法)

UPDATE normalflow_list
SET flow_seqno = flow_seqno + 1
WHERE
    flow_id = '010101'
AND flow_seqno > 2
ORDER BY
    flow_seqno DESC;

• 获取某一列的最大值

  select max(volumu) from table_name
  
  select max(flow_seqno) from normalflow_list where flow_id = '010101';