php的mssql数据库连接类实例

class DB_Sql {
? var $Host???? = "";
? var $Database = "";
? var $User???? = "";
? var $Password = "";
? var $Link_ID? = 0;
? var $Query_ID = 0;
? var $Record?? = array();
? var $Row????? = 0;
??
? var $Errno??? = 0;
? var $Error??? = "";
? var $Auto_Free = 0;???? ## set this to 1 to automatically free results
??
? function DB_Sql($query = "") {
????? $this->query($query);
? }
? function connect() {
??? if ( 0 == $this->Link_ID ) {
????? $this->Link_ID=mssql_connect($this->Host,$this->User,$this->Password);
????? if (!$this->Link_ID)
??????? $this->halt("Link-ID == false,mssql_pconnect failed");
????? else
????????? @mssql_select_db($this->Database,$this->Link_ID);
??? }
? }
? function free_result(){
????? mssql_free_result($this->Query_ID);
????? $this->Query_ID = 0;
? }
??
? function query($Query_String)?
? {
????
??? /* No empty queries,please,since PHP4 chokes on them. */
??? if ($Query_String == "")
????? /* The empty query string is passed on from the constructor,
?????? * when calling the class without a query,e.g. in situations
?????? * like these: '$db = new DB_Sql_Subclass;'
?????? */
????? return 0;
????? if (!$this->Link_ID)
??????? $this->connect();
????
#?? printf("<br>Debug: query = %s<br> ",$Query_String);
?
?$this->Query_ID = mssql_query($Query_String,$this->Link_ID);
??? $this->Row = 0;
??? if (!$this->Query_ID) {
????? $this->Errno = 1;
????? $this->Error = "General Error (The MSSQL interface cannot return detailed error messages).";
????? $this->halt("Invalid SQL: ".$Query_String);
??? }
??? return $this->Query_ID;
? }
??
? function next_record() {
??????
??? if ($this->Record = mssql_fetch_row($this->Query_ID)) {
????? // add to Record[<key>]
????? $count = mssql_num_fields($this->Query_ID);
????? for ($i=0; $i<$count; $i++){
????????? $fieldinfo = mssql_fetch_field($this->Query_ID,$i);
??????? $this->Record[strtolower($fieldinfo->name)] = $this->Record[$i];
????? }
????? $this->Row += 1;
????? $stat = 1;
??? } else {
????? if ($this->Auto_Free) {
??????????? $this->free_result();
????????? }
????? $stat = 0;
??? }
??? return $stat;
? }
??
? function seek($pos) {
??????? mssql_data_seek($this->Query_ID,$pos);
????? $this->Row = $pos;
? }
? function metadata($table) {
??? $count = 0;
??? $id??? = 0;
??? $res?? = array();
??? $this->connect();
??? $id = mssql_query("select * from $table",$this->Link_ID);
??? if (!$id) {
????? $this->Errno = 1;
????? $this->Error = "General Error (The MSSQL interface cannot return detailed error messages).";
????? $this->halt("Metadata query failed.");
??? }
??? $count = mssql_num_fields($id);
????
??? for ($i=0; $i<$count; $i++) {
??????? $info = mssql_fetch_field($id,$i);
????? $res[$i]["table"] = $table;
????? $res[$i]["name"]? = $info["name"];
????? $res[$i]["len"]?? = $info["max_length"];
????? $res[$i]["flags"] = $info["numeric"];
??? }
??? $this->free_result();
??? return $res;
? }
??
? function affected_rows() {
// Not a supported function in PHP3/4.? Chris Johnson,16May2001.
//??? return mssql_affected_rows($this->Query_ID);
??? $rsRows = mssql_query("Select @@rowcount as rows",$this->Link_ID);
??? if ($rsRows) {???????
?????? return mssql_result($rsRows,"rows");
??? }
? }
??
? function num_rows() {
??? return mssql_num_rows($this->Query_ID);
? }
??
? function num_fields() {
??? return mssql_num_fields($this->Query_ID);
? }
? function nf() {
??? return $this->num_rows();
? }
??
? function np() {
??? print $this->num_rows();
? }
??
? function f($Field_Name) {
??? return $this->Record[strtolower($Field_Name)];
? }
??
? function p($Field_Name) {
??? print $this->f($Field_Name);
? }
??
? function halt($msg) {
??? printf("</td></tr></table><b>Database error:</b> %s<br> ",$msg);
??? printf("<b>MSSQL Error</b>: %s (%s)<br> ",
????? $this->Errno,
????? $this->Error);
??? die("Session halted.");
? }
}