С чего начать изучение SQL

if(!mysql_real_connect(&conn, "localhost", "root", "", "InOut", 0, NULL, 0))
{
...
}

if(mysql_ping(&conn)!=0)
{
...
reconnect
...
}

SELECT TOP(100) * FROM database.dbo.MyTable

$res = mssql_query("Select dbo.Payments.PM_ID, dbo.Payments.PM_DocNumber, dbo.Payments.PM_SumTarget, dbo.Clients.CL_FirstName, dbo.Clients.CL_MiddleName, dbo.Clients.CL_Name, dbo.Countries.CN_Name
                    from dbo.Payments, dbo.Clients, dbo.Agreements, dbo.Countries
                    where dbo.Payments.PM_Date='3/15/2011 12:00:00 AM' and dbo.Payments.PM_SumTarget>'0' and dbo.Clients.CL_ID=dbo.Payments.PM_CL_ID and
                    dbo.Agreements.AG_Code=dbo.Payments.PM_DocNumber and dbo.Countries.CN_ID=dbo.Agreements.AG_CN_ID
                    group by dbo.Payments.PM_ID, dbo.Payments.PM_DocNumber, dbo.Payments.PM_SumTarget, dbo.Clients.CL_FirstName, dbo.Clients.CL_MiddleName, dbo.Clients.CL_Name, dbo.Countries.CN_Name");

while ( $w = mssql_fetch_array($res) )
{
echo "<tr>";
echo "<td>".$w["PM_ID"]."</td><td>".$w["PM_DocNumber"]."</td><td>".$w["PM_SumTarget"]."</td><td>".$w["CL_FirstName"]."</td><td>".$w["CL_MiddleName"]."</td><td>".$w["CL_Name"]."</td><td>".$w["CN_Name"]."</td>";
echo "</tr>";
}

_bstr_t strConn = "Provider=sqloledb;Data Source=(local);Initial Catalog=pubs";

Select Number
from dbo.Num
where Number='*1234'