PHP 操作MYSQL基礎知識

mysql_connect() resource mysql_connect([string hostname [:port] [:/path/to/socket] [, string username] [, string password]]) 樣本：$conn = @mysql_connect("localhost", "username", "password") or dir("不能串連到Mysql Server"); 使用該串連必須顯示的關閉串連 複製代碼 建立資料庫連接 mysql_pconnect() resource mysql_pconnect([string hostname [:port] [:/path/to/socket] [, string username] [, string password]]) 樣本：$conn = @mysql_pconnect("localhost", "username", "password") or dir("不能串連到Mysql Server"); 使用該串連函數不需要顯示的關閉串連，它相當於使用了串連池 複製代碼 關閉資料庫連接 mysql_close() $conn = @mysql_connect("localhost", "username", "password") or die("不能串連到Mysql Server"); @mysql_select_db("MyDatabase") or die("不能選擇這個資料庫，或資料庫不存在"); echo "你已經串連到MyDatabase資料庫"; mysql_close(); 複製代碼 選擇資料庫 mysql_select_db() boolean mysql_select_db(string db_name [, resource link_id]) $conn = @mysql_connect("localhost", "username", "password") or die("不能串連到Mysql Server"); @mysql_select_db("MyDatabase") or die("不能選擇這個資料庫，或資料庫不存在"); 複製代碼 查詢MySQL mysql_query() resource mysql_query (string query, [resource link_id]) $linkId = @mysql_connect("localhost", "username", "password") or die("不能串連到Mysql Server"); @mysql_select_db("MyDatabase") or die("不能選擇這個資料庫，或者資料庫不存在"); $query = "select * from MyTable"; $result = mysql_query($query); mysql_close(); 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 複製代碼 查詢MySQL mysql_db_query() resource mysql_db_query(string database, string query [, resource link_id]) $linkId = @mysql_connect("localhost", "username", "password") or die("不能串連到MysqlServer"); $query = "select * from MyTable"; $result = mysql_db_query("MyDatabase", $query); mysql_close(); 為了使代碼清晰，不推薦使用這個函數調用 複製代碼 擷取和顯示資料 mysql_result() mixed mysql_result (resource result_set, int row [, mixed field]) $query = "select id, name from MyTable order by name"; $result = mysql_query($query); $c_id = mysql_result($result, 0, "id"); $c_name = mysql_result($result, 0, "name"); 最簡單、也是效率最低的資料擷取函數 複製代碼 擷取和顯示資料 mysql_fetch_row() array mysql_fetch_row (resource result_set) $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) "); } 函數從result_set中擷取整個資料行，將值放在一個索引數組中。通常會結使list()函數使用 複製代碼 擷取和顯示資料 mysql_fetch_array() array mysql_fetch_array (resource result_set [, int result_type]) $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) "; } result_type的值有： MYSQL_ASSOC: 欄位名表示鍵，欄位內容為值 MYSQL_NUM: 數值索引數組，操作與mysql_fetch_ros()函數一樣 MYSQL_BOTH: 即作為關聯陣列又作為數值索引數組返回。result_type的預設值。 複製代碼 擷取和顯示資料 mysql_fetch_assoc() array mysql_fetch_assoc (resource result_set) 相當於調用 mysql_fetch_array(resource, MYSQL_ASSOC); 複製代碼 擷取和顯示資料 mysql_fetch_object() object mysql_fetch_object(resource result_set) $query = "select id, name from MyTable order by name"; while ($row = mysql_fetch_object($result)) { $id = $row->id; $name = $row->name; echo "Name: $name ($id) "; } 在操作上與mysql_fetch_array()相同 複製代碼 所選擇的記錄 mysql_num_rows() int mysql_num_rows(resource result_set) #query = "select id, name from MyTable where id > 65"; $result = mysql_query($query); echo "有".mysql_num_rows($result)."條記錄的ID大於65"; 只在確定select查詢所擷取的記錄數時才有用。 複製代碼 受影響的記錄 mysql_affected_rows() int mysql_affected_rows([resource link_id]) $query = "update MyTable set name="CheneyFu" where id>=5"; $result = mysql_query($query); echo "ID大於等於5的名稱被更新了的記錄數：".mysql_affected_rows(); 該函數擷取受INSERT,UPDATE或DELETE更新語句影響的行數 複製代碼 擷取資料庫列表資訊 mysql_list_dbs() resource mysql_list_dbs([resource link_id]) mysql_connect("localhost", "username", "password"); $dbs = mysql_list_dbs(); echo "Databases: "; while (list($db) = mysql_fetch_rows($dbs)) { echo "$db "; } 複製代碼 擷取資料庫名 mysql_db_name() string mysql_db_name(resource result_set, integer index) 該函數擷取在mysql_list_dbs()所返回result_set中位於指定index索引的資料庫名 複製代碼 擷取資料庫表列表 mysql_list_tables() resource mysql_list_tables(string database [, resource link_id]) mysql_connect("localhost", "username", "password"); $tables = mysql_list_tables("MyDatabase"); while (list($table) = mysql_fetch_row($tables)) { echo "$table "; }該函數擷取database中所有表的表名 複製代碼 擷取資料庫表名 mysql_tablename() string mysql_tablename(resource result_set, integer index) mysql_connect("localhost", "username", "password"); $tables = mysql_list_tables("MyDatabase"); $count = -1; while (++$count < mysql_numrows($tables)) { echo mysql_tablename($tables, $count)." "; } 該函數擷取mysql_list_tables()所返回result_set中位於指定index索引的表名 複製代碼 擷取欄位資訊 mysql_fetch_field() object mysql_fetch_field(resource result [, int field_offset]) mysql_connect("localhost", "username", "password"); mysql_select_db("MyDatabase"); $query = "select * from MyTable"; $result = mysql_query($query); $fields = mysql_num_fields($result); for($count = 0; $count < $fieds; $count++) { $field = mysql_fetch_field($result, $count); echo " $field->name $field->type ($field->max_length) "; } 複製代碼 返回的對象共有12個對象屬性：name: 欄位名table: 欄位所在的表max_length: 欄位的最大長度not_null: 如果欄位不能為null，則為1，否則0primary_key: 如果欄位為主鍵，則為1，否則0unique_key: 如果欄位是唯一鍵，則為1， 否則0multiple_key: 如果欄位為非唯一，則為1，否則0numeric: 如果欄位為數值則為1，否則0blob: 如果欄位為BLOB則為1，否則為0type: 欄位的資料類型unsigned: 如果欄位為無符號數則為1，否則為0zerofill: 如果欄位為“零填充”則為1， 否則為0 擷取查詢的欄位數 mysql_num_fields() integer mysql_num_fields (resource result_set) $query = "select id, name from MyTable order by name"; $result = mysql_query($query); echo "這個查詢的欄位數是：".mysql_num_fields($result)." "; 複製代碼 返回查詢result_set中的欄位數 擷取指定表的所有欄位的欄位名 mysql_list_fields() resource mysql_list_fields (string database_name, string table_name [, resource link_id]) $fields = mysql_list_fields("MyDatabase", "MyTable"); echo "資料庫MyDatabase中表MyTable的欄位數： ".mysql_num_fields($fields)." "; 複製代碼 擷取指定的欄位選項 mysql_field_flags() string mysql_field_flags (resource result_set, integer field_offset) 複製代碼 擷取指定的欄位的最大長度 mysql_field_len() integer mysql_field_len (resource result_set, integer field_offset) $query = "select name from MyTable"; $result = mysql_query($query); $row = mysql_fetch_row($result); echo mysql_field_len($result, 0)." "; 如果mysql_field_len($reseult, 0) = 16777215 那麼numer_format(mysql_field_len($result))等於16,777,215 複製代碼 擷取欄位名 mysql_field_name() string mysql_field_name (resource result_set, int field_offset) $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 複製代碼 擷取欄位類型 mysql_field_type() string mysql_field_type (resource result_set, int field_offset) $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 複製代碼 擷取欄位所在表名 mysql_field_table() string mysql_field_table (resource result_set, int field_offset) $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 複製代碼

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