PHP中的常用的25個(gè)MYSQL函數(shù)
1、mysql_connect()-建立數(shù)據(jù)庫(kù)連接格式:resource mysql_connect([string hostname [:port] [:/path/to/socket] [, string username] [, string password]])例:$conn = @mysql_connect(”localhost”, “username”, “password”) or dir(”不能連接到Mysql Server”);說(shuō)明:使用該連接必須顯示的關(guān)閉連接
2、mysql_pconnect()-建立數(shù)據(jù)庫(kù)連接格式:resource mysql_pconnect([string hostname [:port] [:/path/to/socket] [, string username] [, string password]])例:$conn = @mysql_pconnect(”localhost”, “username”, “password”) or dir(”不能連接到Mysql Server”);說(shuō)明:使用該連接函數(shù)不需要顯示的關(guān)閉連接,它相當(dāng)于使用了連接池
3、mysql_close()-關(guān)閉數(shù)據(jù)庫(kù)連接例:$conn = @mysql_connect(”localhost”, “username”, “password”) or die(”不能連接到Mysql Server”);@mysql_select_db(”MyDatabase”) or die(”不能選擇這個(gè)數(shù)據(jù)庫(kù),或數(shù)據(jù)庫(kù)不存在”);echo “你已經(jīng)連接到MyDatabase數(shù)據(jù)庫(kù)”;mysql_close();
4、mysql_select_db()-選擇數(shù)據(jù)庫(kù)格式:boolean mysql_select_db(string db_name [, resource link_id])例:$conn = @mysql_connect(”localhost”, “username”, “password”) or die(”不能連接到Mysql Server”);@mysql_select_db(”MyDatabase”) or die(”不能選擇這個(gè)數(shù)據(jù)庫(kù),或數(shù)據(jù)庫(kù)不存在”);
5、mysql_query()-查詢(xún)MySQL格式:resource mysql_query (string query, [resource link_id])例:$linkId = @mysql_connect(”localhost”, “username”, “password”) or die(”不能連接到Mysql Server”);@mysql_select_db(”MyDatabase”) or die(”不能選擇這個(gè)數(shù)據(jù)庫(kù),或者數(shù)據(jù)庫(kù)不存在”);$query = “select * from MyTable”;$result = mysql_query($query);mysql_close();說(shuō)明:若SQL查詢(xún)執(zhí)行成功,則返回資源標(biāo)識(shí)符,失敗時(shí)返回FALSE。若執(zhí)行更新成功,則返回TRUE,否則返回FALSE
6、mysql_db_query()-查詢(xún)MySQL格式:resource mysql_db_query(string database, string query [, resource link_id])例:$linkId = @mysql_connect(”localhost”, “username”, “password”) or die(”不能連接到MysqlServer”);$query = “select * from MyTable”;$result = mysql_db_query(”MyDatabase”, $query);mysql_close();說(shuō)明:為了使代碼清晰,不推薦使用這個(gè)函數(shù)調(diào)用
7、mysql_result()-獲取和顯示數(shù)據(jù)格式:mixed mysql_result (resource result_set, int row [, mixed field])例:$query = “select id, name from MyTable order by name”;$result = mysql_query($query);for($count=0;$count<=mysql_numrows($result);$count++){ $c_id = mysql_result($result, 0, “id”); $c_name = mysql_result($result, 0, “name”); echo $c_id,$c_name;}說(shuō)明:最簡(jiǎn)單、也是效率最低的數(shù)據(jù)獲取函數(shù)
8、mysql_fetch_row()-獲取和顯示數(shù)據(jù)格式:array mysql_fetch_row (resource result_set)例:$query = “select id, name from MyTable order by name”;$result = mysql_query($query);while (list($id, $name) = mysql_fetch_row($result)) { echo(”Name: $name ($id) <br />”);}說(shuō)明:函數(shù)從result_set中獲取整個(gè)數(shù)據(jù)行,將值放在一個(gè)索引數(shù)組中。通常會(huì)結(jié)使list()函數(shù)使用
9、mysql_fetch_array()-獲取和顯示數(shù)據(jù)格式:array mysql_fetch_array (resource result_set [, int result_type])例:$query = “select id, name from MyTable order by name”;$result = mysql_query($query);while($row = mysql_fetch_array($result, MYSQL_ASSOC)) { $id = $row['id']; $name = $row['name']; echo “Name: $name ($id) <br />”;}又例:$query = “select id, name from MyTable order by name”;$result = mysql_query($query);while($row = mysql_fetch_array($result, MYSQL_NUM)) { $id = $row[0]; $name = $row[1]; echo “Name: $name ($id) <br />”;}說(shuō)明:result_type的值有:MYSQL_ASSOC: 字段名表示鍵,字段內(nèi)容為值MYSQL_NUM: 數(shù)值索引數(shù)組,操作與mysql_fetch_ros()函數(shù)一樣MYSQL_BOTH: 即作為關(guān)聯(lián)數(shù)組又作為數(shù)值索引數(shù)組返回。result_type的默認(rèn)值。
10、mysql_fetch_assoc()-獲取和顯示數(shù)據(jù)格式:array mysql_fetch_assoc (resource result_set)相當(dāng)于調(diào)用 mysql_fetch_array(resource, MYSQL_ASSOC);
11、mysql_fetch_object()-獲取和顯示數(shù)據(jù)格式:object mysql_fetch_object(resource result_set)例:$query = “select id, name from MyTable order by name”;while ($row = mysql_fetch_object($result)) { $id = $row->id; $name = $row->name; echo “Name: $name ($id) <br />”;}說(shuō)明:返回一個(gè)對(duì)象,在操作上與mysql_fetch_array()相同
12、mysql_num_rows()-所選擇的記錄的個(gè)數(shù)格式:int mysql_num_rows(resource result_set)例:query = “select id, name from MyTable where id > 65″;$result = mysql_query($query);echo “有”.mysql_num_rows($result).”條記錄的ID大于65″;說(shuō)明:只在確定select查詢(xún)所獲取的記錄數(shù)時(shí)才有用。
13、mysql_affected_rows()-受Insert,update,delete影響的記錄的個(gè)數(shù)格式:int mysql_affected_rows([resource link_id])例:$query = “update MyTable set name=’CheneyFu’ where id>=5″;$result = mysql_query($query);echo “ID大于等于5的名稱(chēng)被更新了的記錄數(shù):”.mysql_affected_rows();說(shuō)明:該函數(shù)獲取受INSERT,UPDATE或DELETE更新語(yǔ)句影響的行數(shù)http://www.mypchelp.cn/php.asp14、mysql_list_dbs()-獲取數(shù)據(jù)庫(kù)列表信息格式:resource mysql_list_dbs([resource link_id])例:mysql_connect(”localhost”, “username”, “password”);$dbs = mysql_list_dbs();echo “Databases: <br />”;while (list($db) = mysql_fetch_rows($dbs)) { echo “$db <br />”;}說(shuō)明:顯示所有數(shù)據(jù)庫(kù)名稱(chēng)
15、mysql_db_name()-獲取數(shù)據(jù)庫(kù)名格式:string mysql_db_name(resource result_set, integer index)說(shuō)明:該函數(shù)獲取在mysql_list_dbs()所返回result_set中位于指定index索引的數(shù)據(jù)庫(kù)名
16、mysql_list_tables()-獲取數(shù)據(jù)庫(kù)表列表格式:resource mysql_list_tables(string database [, resource link_id])例:mysql_connect(”localhost”, “username”, “password”);$tables = mysql_list_tables(”MyDatabase”);while (list($table) = mysql_fetch_row($tables)) { echo “$table <br />”;}說(shuō)明:該函數(shù)獲取database中所有表的表名
17、mysql_tablename()-獲取某個(gè)數(shù)據(jù)庫(kù)表名格式:string mysql_tablename(resource result_set, integer index)例:mysql_connect(”localhost”, “username”, “password”);$tables = mysql_list_tables(”MyDatabase”);$count = -1;while (++$count < mysql_numrows($tables)) { echo mysql_tablename($tables, $count).”<br />”;}說(shuō)明:該函數(shù)獲取mysql_list_tables()所返回result_set中位于指定index索引的表名
18、mysql_fetch_field()-獲取字段信息格式:object mysql_fetch_field(resource result [, int field_offset])例:mysql_connect(”localhost”, “username”, “password”);mysql_select_db(”MyDatabase”);$query = “select * from MyTable”;$result = mysql_query($query);$counts = mysql_num_fields($result);for($count = 0; $count < $counts; $count++) { $field = mysql_fetch_field($result, $count); echo “<p>$field->name $field->type ($field->max_length) </p>”;}說(shuō)明:返回的對(duì)象共有12個(gè)對(duì)象屬性:name: 字段名table: 字段所在的表max_length: 字段的最大長(zhǎng)度not_null: 如果字段不能為null,則為1,否則0primary_key: 如果字段為主鍵,則為1,否則0unique_key: 如果字段是唯一鍵,則為1, 否則0multiple_key: 如果字段為非唯一,則為1,否則0numeric: 如果字段為數(shù)值則為1,否則0blob: 如果字段為BLOB則為1,否則為0type: 字段的數(shù)據(jù)類(lèi)型unsigned: 如果字段為無(wú)符號(hào)數(shù)則為1,否則為0zerofill: 如果字段為“零填充”則為1, 否則為0
19、mysql_num_fields()-獲取查詢(xún)的字段個(gè)數(shù)格式:integer mysql_num_fields (resource result_set)例:$query = “select id, name from MyTable order by name”;$result = mysql_query($query);echo “這個(gè)查詢(xún)的字段數(shù)是:”.mysql_num_fields($result).”<br />”;
20、mysql_list_fields()-獲取指定表的所有字段的字段名格式:resource mysql_list_fields (string database_name, string table_name [, resource link_id])例:$fields = mysql_list_fields(”MyDatabase”, “MyTable”);echo “數(shù)據(jù)庫(kù)MyDatabase中表MyTable的字段數(shù): “.mysql_num_fields($fields).”<br />”;
21、mysql_field_flags()-獲取指定的字段選項(xiàng)格式:string mysql_field_flags (resource result_set, integer field_offset)例:$query = “select id, name from MyTable order by name”;$result = mysql_query($query);$row=mysql_fetch_wor($row);
22、mysql_field_len()-獲取指定的字段的最大長(zhǎng)度格式:integer mysql_field_len (resource result_set, integer field_offset)例:$query = “select name from MyTable”;$result = mysql_query($query);$row = mysql_fetch_row($result);echo mysql_field_len($result, 0).”<br />”;說(shuō)明:如果mysql_field_len($reseult, 0) = 16777215那么numer_format(mysql_field_len($result))等于16,777,215
23、mysql_field_name()-獲取字段名格式:string mysql_field_name (resource result_set, int field_offset)例:$query = “select id as PKID, name from MyTable order by name”;$result = mysql_query($query);$row = mysql_fetch_row($result);echo mysql_field_name($result, 0); // Result: PKID
24、mysql_field_type()-獲取字段類(lèi)型格式:string mysql_field_type (resource result_set, int field_offset)例:$query = “select id, name from MyTable order by name”;$result = mysql_query($query);$row = mysql_fetch_row($result);echo mysql_field_type($result, 0); // Result: int
25、mysql_field_table()-獲取字段所在表名格式:string mysql_field_table (resource result_set, int field_offset)例:$query = “select id as PKID, name from MyTable order by name”;$result = mysql_query($query);$row = mysql_fetch_row($result);echo mysql_field_table($result, 0); // Result: MyTable
