C#数据库连接字符串
Web.config文件
<connectionStrings>
<!--SQLServer数据库连接-->
<add name="conn_test_sqlserver" connectionString="server=127.0.0.1;uid=testuser;pwd=testPwd;database=db_test;pooling=true;min pool size=10;max pool size=1024;connection lifetime=300;packet size=1000" providerName="System.Data.SqlClient"/>
<!--MySQL数据库连接-->
<add name="conn_test_mysql" connectionString="Data Source=127.0.0.1; Database=db_test; User Id=testuser;Password=testPwd; pooling=false; CharSet=utf8; Port=3306" providerName="MySql.Data.MySqlClient"/>
<!--SQLite数据库连接-->
<add name="conn_test_sqlite" connectionString="Data Source=|DataDirectory|\db_test.db3; Pooling=true; FailIfMissing=false" providerName="System.Data.SQLite" />
</connectionStrings>
<!-- 解决DbProviderFactories.GetFactory(ProviderName)出现的异常：“找不到请求的 .Net Framework Data Provider。可能没有安装。” -->
<system.data>
<DbProviderFactories>
<remove invariant="System.Data.SQLite"/>
<add name="SQLite Data Provider" invariant="System.Data.SQLite" description=".Net Framework Data Provider for SQLite" type="System.Data.SQLite.SQLiteFactory, System.Data.SQLite, Version=1.0.105.2, Culture=neutral, PublicKeyToken=db937bc2d44ff139" />
<remove invariant="MySQL Data Provider"/>
<add name="MySQL Data Provider" invariant="MySql.Data.MySqlClient" description=".Net Framework Data Provider for MySQL" type="MySql.Data.MySqlClient.MySqlClientFactory, MySql.Data, Version=6.9.9.0, Culture=neutral, PublicKeyToken=c5687fc88969c44d" />
</DbProviderFactories>
</system.data>
示例代码：
protected void Page_Load(object sender, EventArgs e)
{
try
{
object value = GetValue();
Response.Write(null==value?"Null":value);
}
catch (Exception ex)
{
Response.Write(ex.Message);
}
}
public object GetValue()
{
string connName = "con_test_mysql";
System.Configuration.ConnectionStringSettings connConf = System.Configuration.ConfigurationManager.ConnectionStrings[connName];
DbFactory dbFactory = new DbFactory(connConf.ProviderName, connConf.ConnectionString);
try
{
System.Data.Common.DbProviderFactory dbpf = System.Data.Common.DbProviderFactories.GetFactory(connConf.ProviderName);
using (System.Data.Common.DbConnection conn = dbpf.CreateConnection())
{
conn.ConnectionString = connConf.ConnectionString;
using (System.Data.Common.DbCommand cmd = conn.CreateCommand())
{
// cmd
string sqlstmt = "select remark from t_user where account=@account";
cmd.CommandText = sqlstmt;
cmd.CommandTimeout = ;
// params
System.Data.Common.DbParameter dbpara = cmd.CreateParameter();
dbpara.ParameterName = "@account";
dbpara.Value = "test@email.com";
dbpara.Size = ;
cmd.Parameters.Add(dbpara);
// execute
System.Data.Common.DbDataAdapter dbadp = dbpf.CreateDataAdapter();
dbadp.SelectCommand = cmd;
conn.Open();
DataTable dtResult = new DataTable();
dbadp.Fill(dtResult);
object value = null;
if (dtResult.Rows.Count > )
{
value = dtResult.Rows[][];
if (DBNull.Value == value)
{
value = null;
}
}
return value;
}
}
}
catch (Exception ex)
{
throw ex;
}
}
下载： CSharpDbConnectionDemo(DotNet数据库连接演示).zip
Java数据库连接字符串
// mysql
driver="com.mysql.jdbc.Driver";
url = "jdbc:mysql://localhost:3306/db_test?useUnicode=true&characterEncoding=UTF8";
conn = getConnection(driver,url, "user", "password");
System.out.println("与mysql数据库连接" + (null == conn ? "失败" : "成功"));
// sqlite
driver="SQLite.JDBCDriver";
url = "jdbc:sqlite:/C:/db_test.db3";
conn = getConnection(driver,url);
System.out.println("与sqlite数据库连接" + (null == conn ? "失败" : "成功"));
// sqlserver
driver="com.mysql.jdbc.Driver";
url = "jdbc:sqlserver://localhost:1433;DatabaseName=db_test";
conn = getConnection(driver,url, "user", "password");
System.out.println("与sql server数据库连接" + (null == conn ? "失败" : "成功"));
// oracle
driver="oracle.jdbc.driver.OracleDriver";
url = "jdbc:oracle:thin:@localhost:1521:orcl";
conn = getConnection(driver,url, "user", "password");
System.out.println("与oracle数据库连接" + (null == conn ? "失败" : "成功"));
JDBC连接数据库方法
public static Connection getConnection(String driver, String url, String user, String password) {
Connection conn = null;
try {
//初始化驱动包
Class.forName(driver);
conn = DriverManager.getConnection(url, user, password);
} catch (Exception e) {
e.printStackTrace();
}
return conn;
}
下载：[jdbc_connection_demo(JDBC连接各种数据库演示).zip]
PHP_PDO数据库连接字符串
// PDO连接MySQL的DSN字符串 (需要打开php配置文件中的"extension=php_pdo_mysql.dll"选项)
mysql:dbname=db_test;host=127.0.0.1;port=3306;charset=utf8
// PDO连接SQLite的DSN字符串 (需要打开php配置文件中的"extension=php_pdo_sqlite.dll"选项)
sqlite:test_db.db3
// PDO通过ODBC连接SQL Server的DSN字符串 (需要打开php配置文件中的"extension=php_pdo_odbc.dll"选项)
odbc:Driver={SQL Server};Server=127.0.0.1,1433;Database=db_test;
// PDO连接SQL Server的DSN字符串（配置非常麻烦，建议使用ODBC方式。PHP5.3.6以上的版本中php_mssql.dll，php_pdo_mssql.dll都已经不见了,只有一个php_pdo_odbc.dll,所以最新最好的php连接mssql方法应该是使用ODBC的驱动模式。）
sqlsrv:Database=db_test;Server=127.0.0.1,1433
// PDO连接PostgreSQL的DSN字符串 (需要打开php配置文件中的"extension=php_pdo_pgsql.dll"选项)
pgsql:dbname=db_test;host=127.0.0.1;port=5432
// PDO连接Oracle的DSN字符串 (需要打开php配置文件中的"extension=php_pdo_oci.dll"选项)
oci:dbname=//127.0.0.1:5432/db_test
示例代码：
$dsn = 'mysql:dbname=db_test;host=127.0.0.1;port=3306;charset=utf8';
$pdo = new PDO($dsn, 'dbuser', 'dbpwd');
$stmt = $pdo->prepare('select id, name from t_user where user_name=:account');
$stmt->bindParam(':account', $account);
$stmt->execute();
while ($row = $stmt->fetch()) {
return $row;
}
/**
* 查询并返回数组
* <br />例如：
* <br />query('select COLUMN_NAME, IS_NULLABLE, DATA_TYPE, CHARACTER_MAXIMUM_LENGTH, NUMERIC_PRECISION, NUMERIC_SCALE, EXTRA, COLUMN_COMMENT from information_schema.columns WHERE TABLE_SCHEMA=:database AND TABLE_NAME=:table', ['database' => $dbname, 'table' => $tablename])
* @param string $sqlstmt
* @param array $params
* @return array
*/
function query($sqlstmt, $params = []) {
$dsn = 'mysql:host=127.0.0.1;port=3306;charset=utf8';
$pdo = new PDO($dsn, 'dbuser', 'dbpwd');
$stmt = $pdo->prepare($sqlstmt);
if ($params) {
$names = array_keys($params);
$values = array_values($params);
$i = count($names) - 1;
// 这里不能用foreach，参考bindParam陷阱(值参数是引用型变量)：http://www.laruence.com/2012/10/16/2831.html
while ($i >= 0) {
$stmt->bindParam($names[$i], $values[$i]);
$i--;
}
}
$stmt->execute();
$out = [];
while ($row = $stmt->fetch()) {
$out[] = $row;
}
return $out;
}
下载：[pdo_dns_demo(PDO连接各种数据库演示).zip]
PHP官方DSN说明：http://php.net/manual/en/ref.pdo-odbc.connection.php
更多DSN连接字符串可以参考：http://www.connectionstrings.com/
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