Question

I have two tables in different mysql databases.

I would like to copy from table A to table B. Only one way.
I need to read last datetime from table B and then check if there any data added to table A after this readed datetime. If there is some data added, then copy it.

I tried this:

It writes one row if I refresh page, but I need it to write everything in one load!

do
   {

#TABLE A    
$querylastA = "SELECT * FROM `stock` ORDER BY `jrk` DESC LIMIT 1";
$resultlastA = mysql_query($querylastA) or die(mysql_error());
while($rows=mysql_fetch_array($resultlastA)){
$lastcodeA = $rows['datetime'];
}

#TABLE B
$querylastB = "SELECT * FROM `stockcopy` ORDER BY `jrk` DESC LIMIT 1";
$resultlastB = mysql_query($querylastB) or die(mysql_error());
while($rows=mysql_fetch_array($resultlastB)){
$lastcodeB = $rows['datetime'];
}

#TABLE A - NEXT DATE AFTER LAST DATE IN TABLE B
$querynextA = "SELECT datetime FROM stock WHERE datetime > '$lastcodeB' ORDER BY datetime ASC LIMIT 1";
$resultnextA = mysql_query($querynextA) or die(mysql_error());
while($rows=mysql_fetch_array($resultnextA)){
$nextcodeA = $rows['datetime'];
}


   mysql_query("INSERT INTO stockcopy(datetime, data1, data2) SELECT datetime, data1, data2 FROM stock WHERE datetime = '$nextcodeA'");
   echo "Date from table A " . $lastcodeA . "<br>";
   echo "Date from table B " . $lastcodeB . "<br>";
   }
 while ('$lastcodeA' == '$lastcodeB');

Answer 1

You can insert data on a table using a SELECT statement, so all you need to do is put the condition in the SELECT.

For instance:

INSERT INTO table_example(foo, bar)
SELECT foo, bar FROM table_example2
WHERE time_condition > {SOME DATE}

This will insert into table_example the rows that the SELECT statement returns, which are the ones that satisfy the time condition. You will need to replace {SOME DATE} with an actual date (without brackets).

Also, please see: INSERT with SELECT

And also: Select columns across different databases