请问sql语句写法-php教程

请教sql语句写法？
$sql1是根据用户输入选择值动态生成的:


$COnditionsNumber=6;
$COnditionsArray=array( "$condition1 ", "$condition2 ", "$condition3 ", "$condition4 ", "$condition5 ", "$condition6 ");
$SearchSQLArray=array( " where ip= &＃39;$condition1 &＃39; ", " where bianhao= &＃39;$condition2 &＃39; ", " where name= &＃39;$condition3 &＃39; ", " where user= &＃39;$condition4 &＃39; ", " where bankid= &＃39;$condition5 &＃39; ", " where equimode= &＃39;$condition6 &＃39; ");

for($i=0;$i <$ConditionsNumber;$i++)
{
if($ConditionsArray[$i]== " ")
$SearchSQLArray[$i]= " ";
$haveWhere=false;
for($j=0;$j <$i;$j++)
{
$wherePosition=strpos($SearchSQLArray[$j], "where ");
if(($wherePosition== "1 ")&&($haveWhere==false))
{
$SearchSQLArray[$i]=ereg_replace( "where ", "and ",$SearchSQLArray[$i]);
$haveWhere=true;
}
}
};

for($i=0;$i <$ConditionsNumber;$i++)

$sql1=$sql1.$SearchSQLArray[$i];

$sql = "select * from oareport ".$sql1. "; ";