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PHP中的常用的25個MYSQL函數

瀏覽：12日期：2024-01-15 15:47:42

1、mysql_connect()-建立數據庫連接格式：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”);說明：使用該連接必須顯示的關閉連接

2、mysql_pconnect()-建立數據庫連接格式：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”);說明：使用該連接函數不需要顯示的關閉連接，它相當于使用了連接池

3、mysql_close()-關閉數據庫連接例：$conn = @mysql_connect(”localhost”, “username”, “password”) or die(”不能連接到Mysql Server”);@mysql_select_db(”MyDatabase”) or die(”不能選擇這個數據庫，或數據庫不存在”);echo “你已經連接到MyDatabase數據庫”;mysql_close();

4、mysql_select_db()-選擇數據庫格式：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(”不能選擇這個數據庫，或數據庫不存在”);

5、mysql_query()-查詢MySQL格式：resource mysql_query (string query, [resource link_id])例：$linkId = @mysql_connect(”localhost”, “username”, “password”) or die(”不能連接到Mysql Server”);@mysql_select_db(”MyDatabase”) or die(”不能選擇這個數據庫，或者數據庫不存在”);$query = “select * from MyTable”;$result = mysql_query($query);mysql_close();說明：若SQL查詢執行成功，則返回資源標識符，失敗時返回FALSE。若執行更新成功，則返回TRUE，否則返回FALSE

6、mysql_db_query()-查詢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();說明：為了使代碼清晰，不推薦使用這個函數調用

7、mysql_result()-獲取和顯示數據格式：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;}說明：最簡單、也是效率最低的數據獲取函數

8、mysql_fetch_row()-獲取和顯示數據格式：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) ”);}說明：函數從result_set中獲取整個數據行，將值放在一個索引數組中。通常會結使list()函數使用

9、mysql_fetch_array()-獲取和顯示數據格式：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) ”;}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) ”;}說明：result_type的值有：MYSQL_ASSOC: 字段名表示鍵，字段內容為值MYSQL_NUM: 數值索引數組，操作與mysql_fetch_ros()函數一樣MYSQL_BOTH: 即作為關聯數組又作為數值索引數組返回。result_type的默認值。

10、mysql_fetch_assoc()-獲取和顯示數據格式：array mysql_fetch_assoc (resource result_set)相當于調用 mysql_fetch_array(resource, MYSQL_ASSOC);

11、mysql_fetch_object()-獲取和顯示數據格式：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) ”;}說明：返回一個對象，在操作上與mysql_fetch_array()相同

12、mysql_num_rows()-所選擇的記錄的個數格式：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″;說明：只在確定select查詢所獲取的記錄數時才有用。

13、mysql_affected_rows()－受Insert,update,delete影響的記錄的個數格式：int mysql_affected_rows([resource link_id])例：$query = “update MyTable set name=’CheneyFu’ where id>=5″;$result = mysql_query($query);echo “ID大于等于5的名稱被更新了的記錄數：”.mysql_affected_rows();說明：該函數獲取受INSERT,UPDATE或DELETE更新語句影響的行數http://www.mypchelp.cn/php.asp14、mysql_list_dbs()-獲取數據庫列表信息格式：resource mysql_list_dbs([resource link_id])例：mysql_connect(”localhost”, “username”, “password”);$dbs = mysql_list_dbs();echo “Databases: ”;while (list($db) = mysql_fetch_rows($dbs)) { echo “$db ”;}說明：顯示所有數據庫名稱

15、mysql_db_name()-獲取數據庫名格式：string mysql_db_name(resource result_set, integer index)說明：該函數獲取在mysql_list_dbs()所返回result_set中位于指定index索引的數據庫名

16、mysql_list_tables()-獲取數據庫表列表格式：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 ”;}說明：該函數獲取database中所有表的表名

17、mysql_tablename()-獲取某個數據庫表名格式：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).” ”;}說明：該函數獲取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, $count); echo “$field->name $field->type ($field->max_length) ”;}說明：返回的對象共有12個對象屬性：name: 字段名table: 字段所在的表max_length: 字段的最大長度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: 如果字段為數值則為1，否則0blob: 如果字段為BLOB則為1，否則為0type: 字段的數據類型unsigned: 如果字段為無符號數則為1，否則為0zerofill: 如果字段為“零填充”則為1，否則為0

19、mysql_num_fields()-獲取查詢的字段個數格式：integer mysql_num_fields (resource result_set)例：$query = “select id, name from MyTable order by name”;$result = mysql_query($query);echo “這個查詢的字段數是：”.mysql_num_fields($result).” ”;

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：$fields = mysql_list_fields(”MyDatabase”, “MyTable”);echo “數據庫MyDatabase中表MyTable的字段數： “.mysql_num_fields($fields).” ”;

21、mysql_field_flags()-獲取指定的字段選項格式：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).” ”;說明：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

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