SQL仓库

1. 查表中数据个数

select count(*) from table_name where condition 

2. 删除表中数据

delete from table_name where condition

3.筛选符合条件数据并且将结果根据条件公式求和

SELECT
   sum(case 
   	   when transaction_state ='B' then transaction_amount
   	   when transaction_state ='s' then -transaction_amount 
   end
   )as result
FROM 
    stocktransactiondetail_april 
WHERE 
    stock_symbol ='sz300347' AND (transaction_date ='2024-04-19' or transaction_date ='2024-04-22' or transaction_date ='2024-04-23') AND transaction_amount >1000000;