仅在每个月的第一天插入数据一次

Question

I want to insert data into a table on 1st day of every month. And it has to be just for one time. I mean one row for each 1st day of month. I am doing all this in a PHP file and using mySql.

So far i got this much-

if(Date('j')==1)
{
    $query = select 1 from table where extract (year from t1) = extract(year from now()) and extract(month from t1) = extract(month from now()) LIMIT 1
    if (@mysql_num_rows(mysql_query($query)) == 0)
    {
       //perform insert operation
    }
}

I haven't tried this query till yet.

Answer 1

SELECT DATEADD(mm, DATEDIFF(mm,0,GETDATE())-1,0) as StartOfLastMonth
SELECT DATEADD(mm, DATEDIFF(mm,0,GETDATE()),0) as StartOfThisMonth
SELECT DATEADD(mm, DATEDIFF(mm,0,GETDATE()),0) as StartOfNextMonth