class SQLDBHelper
{
/// <summary>
/// 连接数据库
/// </summary>
private static string connectionString =
"Data Source=.; Initial Catalog=database; UID=sa;PASSWORD=123456;pooling=false; ";
#region 设置数据库链接
/// <summary>
/// 设置数据库链接
/// </summary>
/// <param name="server"></param>
/// <param name="database"></param>
/// <param name="name"></param>
/// <param name="pwd"></param>
/// <param name="pool"></param>
/// <returns></returns>
public static bool SetConn(
string server,
string database,
string name,
string pwd,
string pool)
{
connectionString =
"Data Source=" +
server
+
"; Initial Catalog=" +
database
+
"; UID=" +
name
+
";PWD=" +
pwd
+
"; pooling=" + pool +
";";
using (SqlConnection conn =
new SqlConnection(connectionString))
{
try
{
conn.Open();
return true;
}
catch (Exception E)
{
conn.Close();
return false;
}
}
}
#endregion
#region 测试数据库链接
/// <summary>
/// 测试数据库链接
/// </summary>
/// <returns></returns>
public static bool TestConn()
{
using (SqlConnection conn =
new SqlConnection(connectionString))
{
try
{
conn.Open();
return true;
}
catch (Exception E)
{
conn.Close();
return false;
}
}
}
#endregion
#region 公用获取Connection
/// <summary>
/// //打开连接 并获得 SqlConnection
/// </summary>
public static SqlConnection Connection
{
get
{
SqlConnection conn =
new SqlConnection(connectionString);
if (conn ==
null)
{
conn.Open();
}
else if (conn.State ==
System.Data.ConnectionState.Closed)
{
conn.Open();
}
else if (conn.State ==
System.Data.ConnectionState.Broken)
{
conn.Close();
conn.Open();
}
return conn;
}
}
#endregion
#region 公用方法
/// <summary>
/// 获取某表的某字段的最大值
/// </summary>
/// <param name="fieldName">字段名</param>
/// <param name="tableName">表名</param>
/// <returns></returns>
public static int GetMaxID(
string fieldName,
string tableName)
{
string sqlString =
"select max(" + fieldName +
")+1 from " +
tableName;
object obj =
GetSingle(sqlString);
if (obj ==
null)
{
return 1;
}
else
{
return int.Parse(obj.ToString());
}
}
/// <summary>
/// 查询某个值是否存在
/// </summary>
/// <param name="sqlString">sql</param>
/// <param name="cmdParms">参数</param>
/// <returns></returns>
public static bool Exists(
string sqlString,
params SqlParameter[] cmdParms)
{
object obj =
GetSingle(sqlString, cmdParms);
int cmdResult;
if ((Object.Equals(obj,
null)) ||
(Object.Equals(obj, System.DBNull.Value)))
{
cmdResult =
0;
}
else
{
cmdResult =
int.Parse(obj.ToString());
}
if (cmdResult ==
0)
{
return false;
}
else
{
return true;
}
}
#endregion
#region 执行简单SQL语句
/// <summary>
/// 执行SQL语句，返回影响的记录数
/// </summary>
/// <param name="sqlString">SQL语句</param>
/// <returns>影响的记录数</returns>
public static int ExecuteSql(
string sqlString)
{
using (SqlConnection connection =
new SqlConnection(connectionString))
{
using (SqlCommand cmd =
new SqlCommand(sqlString, connection))
{
try
{
connection.Open();
int rows =
cmd.ExecuteNonQuery();
return rows;
}
catch (System.Data.SqlClient.SqlException E)
{
connection.Close();
throw new Exception(E.Message);
}
finally
{
cmd.Dispose();
connection.Close();
}
}
}
}
/// <summary>
/// 执行多条SQL语句，实现数据库事务。
/// </summary>
/// <param name="sqlStringList">多条SQL语句</param>
public static void ExecuteSqlTran(ArrayList sqlStringList)
{
using (SqlConnection conn =
new SqlConnection(connectionString))
{
conn.Open();
SqlCommand cmd =
new SqlCommand();
cmd.Connection =
conn;
SqlTransaction tx =
conn.BeginTransaction();
cmd.Transaction =
tx;
try
{
for (
int n =
0; n < sqlStringList.Count; n++
)
{
string sqlString =
sqlStringList[n].ToString();
if (sqlString.Trim().Length >
1)
{
cmd.CommandText =
sqlString;
cmd.ExecuteNonQuery();
}
}
tx.Commit();
}
catch (System.Data.SqlClient.SqlException E)
{
tx.Rollback();
throw new Exception(E.Message);
}
finally
{
cmd.Dispose();
conn.Close();
}
}
}
/// <summary>
/// 执行带一个存储过程参数的的SQL语句。
/// </summary>
/// <param name="sqlString">SQL语句</param>
/// <param name="content">参数内容,比如一个字段是格式复杂的文章，有特殊符号，可以通过这个方式添加</param>
/// <returns>影响的记录数</returns>
public static int ExecuteSql(
string sqlString,
string content)
{
using (SqlConnection connection =
new SqlConnection(connectionString))
{
SqlCommand cmd =
new SqlCommand(sqlString, connection);
System.Data.SqlClient.SqlParameter myParameter =
new System.Data.SqlClient.SqlParameter(
"@content",
SqlDbType.NText);
myParameter.Value =
content;
cmd.Parameters.Add(myParameter);
try
{
connection.Open();
int rows =
cmd.ExecuteNonQuery();
return rows;
}
catch (System.Data.SqlClient.SqlException E)
{
throw new Exception(E.Message);
}
finally
{
cmd.Dispose();
connection.Close();
}
}
}
/// <summary>
/// 向数据库里插入图像格式的字段(和上面情况类似的另一种实例)
/// </summary>
/// <param name="sqlString">SQL语句</param>
/// <param name="fs">图像字节,数据库的字段类型为image的情况</param>
/// <returns>影响的记录数</returns>
public static int ExecuteSqlInsertImg(
string sqlString,
byte[] fs)
{
using (SqlConnection connection =
new SqlConnection(connectionString))
{
SqlCommand cmd =
new SqlCommand(sqlString, connection);
System.Data.SqlClient.SqlParameter myParameter =
new System.Data.SqlClient.SqlParameter(
"@fs",
SqlDbType.Image);
myParameter.Value =
fs;
cmd.Parameters.Add(myParameter);
try
{
connection.Open();
int rows =
cmd.ExecuteNonQuery();
return rows;
}
catch (System.Data.SqlClient.SqlException E)
{
throw new Exception(E.Message);
}
finally
{
cmd.Dispose();
connection.Close();
}
}
}
/// <summary>
/// 执行一条计算查询结果语句，返回查询结果（object）。
/// </summary>
/// <param name="sqlString">计算查询结果语句</param>
/// <returns>查询结果（object）</returns>
public static object GetSingle(
string sqlString)
{
using (SqlConnection connection =
new SqlConnection(connectionString))
{
using (SqlCommand cmd =
new SqlCommand(sqlString, connection))
{
try
{
connection.Open();
object obj =
cmd.ExecuteScalar();
if ((Object.Equals(obj,
null)) ||
(Object.Equals(obj, System.DBNull.Value)))
{
return null;
}
else
{
return obj;
}
}
catch (System.Data.SqlClient.SqlException e)
{
connection.Close();
throw new Exception(e.Message);
}
finally
{
cmd.Dispose();
connection.Close();
}
}
}
}
/// <summary>
/// 执行查询语句，返回SqlDataReader
/// </summary>
/// <param name="sqlString">查询语句</param>
/// <returns>SqlDataReader</returns>
public static SqlDataReader ExecuteReader(
string sqlString)
{
SqlConnection connection =
new SqlConnection(connectionString);
SqlCommand cmd =
new SqlCommand(sqlString, connection);
SqlDataReader myReader =
null;
try
{
connection.Open();
myReader =
cmd.ExecuteReader(CommandBehavior.CloseConnection);
return myReader;
}
catch (System.Data.SqlClient.SqlException e)
{
connection.Close();
throw new Exception(e.Message);
}
finally
{
if (myReader ==
null)
{
cmd.Dispose();
connection.Close();
}
}
}
/// <summary>
/// 执行查询语句，返回DataSet
/// </summary>
/// <param name="sqlString">查询语句</param>
/// <returns>DataSet</returns>
public static DataSet GetDataSet(
string sqlString)
{
using (SqlConnection connection =
new SqlConnection(connectionString))
{
DataSet ds =
new DataSet();
try
{
connection.Open();
SqlDataAdapter command =
new SqlDataAdapter(sqlString, connection);
command.Fill(ds, "ds");
}
catch (System.Data.SqlClient.SqlException ex)
{
throw new Exception(ex.Message);
}
finally
{
connection.Close();
}
return ds;
}
}
#endregion
#region 执行带参数的SQL语句
/// <summary>
///
/// </summary>
/// <param name="sqlString"></param>
/// <param name="cmdParms"></param>
/// <returns></returns>
public static int ExecuteSql(
string sqlString,
params SqlParameter[] cmdParms)
{
using (SqlConnection connection =
new SqlConnection(connectionString))
{
using (SqlCommand cmd =
new SqlCommand())
{
try
{
PrepareCommand(cmd, connection, null, sqlString, cmdParms);
int rows =
cmd.ExecuteNonQuery();
cmd.Parameters.Clear();
return rows;
}
catch (System.Data.SqlClient.SqlException E)
{
throw new Exception(E.Message);
}
finally
{
cmd.Dispose();
connection.Close();
}
}
}
}
/// <summary>
/// 执行多条SQL语句，实现数据库事务。
/// </summary>
/// <param name="sqlStringList">SQL语句的哈希表（key为sql语句，value是该语句的SqlParameter[]）</param>
public static void ExecuteSqlTran(Hashtable sqlStringList)
{
using (SqlConnection conn =
new SqlConnection(connectionString))
{
conn.Open();
using (SqlTransaction trans =
conn.BeginTransaction())
{
SqlCommand cmd =
new SqlCommand();
try
{
//循环
foreach (DictionaryEntry myDE
in sqlStringList)
{
string cmdText =
myDE.Key.ToString();
SqlParameter[] cmdParms =
(SqlParameter[])myDE.Value;
PrepareCommand(cmd, conn, trans, cmdText, cmdParms);
int val =
cmd.ExecuteNonQuery();
cmd.Parameters.Clear();
trans.Commit();
}
}
catch
{
trans.Rollback();
throw;
}
finally
{
conn.Close();
}
}
}
}
/// <summary>
/// 执行SQL语句并返回单个值
/// </summary>
/// <param name="sqlString"></param>
/// <param name="cmdParms"></param>
/// <returns></returns>
public static object GetSingle(
string sqlString,
params SqlParameter[] cmdParms)
{
using (SqlConnection connection =
new SqlConnection(connectionString))
{
using (SqlCommand cmd =
new SqlCommand())
{
try
{
PrepareCommand(cmd, connection, null, sqlString, cmdParms);
object obj =
cmd.ExecuteScalar();
cmd.Parameters.Clear();
if ((Object.Equals(obj,
null)) ||
(Object.Equals(obj, System.DBNull.Value)))
{
return null;
}
else
{
return obj;
}
}
catch (System.Data.SqlClient.SqlException e)
{
throw new Exception(e.Message);
}
finally
{
cmd.Dispose();
connection.Close();
}
}
}
}
/// <summary>
/// 获得查询的结果集
/// </summary>
public static SqlDataReader ExecuteReader(
string sqlString,
params SqlParameter[] cmdParms)
{
SqlConnection connection =
new SqlConnection(connectionString);
SqlCommand cmd =
new SqlCommand();
SqlDataReader myReader =
null;
try
{
PrepareCommand(cmd, connection, null, sqlString, cmdParms);
myReader =
cmd.ExecuteReader(CommandBehavior.CloseConnection);
cmd.Parameters.Clear();
return myReader;
}
catch (System.Data.SqlClient.SqlException e)
{
connection.Close();
throw new Exception(e.Message);
}
finally
{
if (myReader ==
null)
{
cmd.Dispose();
connection.Close();
}
}
}
/// <summary>
/// 获得查询的数据集
/// </summary>
public static DataSet GetDataSet(
string sqlString,
params SqlParameter[] cmdParms)
{
using (SqlConnection connection =
new SqlConnection(connectionString))
{
SqlCommand cmd =
new SqlCommand();
PrepareCommand(cmd, connection, null, sqlString, cmdParms);
using (SqlDataAdapter da =
new SqlDataAdapter(cmd))
{
DataSet ds =
new DataSet();
try
{
da.Fill(ds, "ds");
cmd.Parameters.Clear();
}
catch (System.Data.SqlClient.SqlException ex)
{
throw new Exception(ex.Message);
}
finally
{
cmd.Dispose();
connection.Close();
}
return ds;
}
}
}
/// <summary>
/// 装载SqlCommand对象
/// </summary>
private static void PrepareCommand(SqlCommand cmd, SqlConnection conn, SqlTransaction trans,
string cmdText,
SqlParameter[] cmdParms)
{
if (conn.State !=
ConnectionState.Open)
{
conn.Open();
}
cmd.Connection =
conn;
cmd.CommandText =
cmdText;
if (trans !=
null)
{
cmd.Transaction =
trans;
}
cmd.CommandType = CommandType.Text;
//cmdType;
if (cmdParms !=
null)
{
foreach (SqlParameter parm
in cmdParms)
{
cmd.Parameters.Add(parm);
}
}
}
#endregion
#region 存储过程操作
/// <summary>
/// 执行存储过程,返回结果集
/// </summary>
/// <param name="storedProcName">存储过程名</param>
/// <param name="parameters">存储过程参数</param>
/// <returns>SqlDataReader</returns>
public static SqlDataReader RunProcedureForDataReader(
string storedProcName, IDataParameter[] parameters)
{
SqlConnection connection =
new SqlConnection(connectionString);
try
{
SqlDataReader returnReader;
connection.Open();
SqlCommand command =
BuildQueryCommand(connection, storedProcName, parameters);
command.CommandType =
CommandType.StoredProcedure;
returnReader =
command.ExecuteReader(CommandBehavior.CloseConnection);
return returnReader;
}
catch (System.Data.SqlClient.SqlException ex)
{
throw new Exception(ex.Message);
}
finally
{
connection.Close();
}
}
/// <summary>
/// 执行存储过程,返回数据集
/// </summary>
/// <param name="storedProcName">存储过程名</param>
/// <param name="parameters">存储过程参数</param>
/// <returns>DataSet</returns>
public static DataSet RunProcedureForDataSet(
string storedProcName, IDataParameter[] parameters)
{
using (SqlConnection connection =
new SqlConnection(connectionString))
{
DataSet dataSet =
new DataSet();
connection.Open();
SqlDataAdapter sqlDA =
new SqlDataAdapter();
sqlDA.SelectCommand =
BuildQueryCommand(connection, storedProcName, parameters);
sqlDA.Fill(dataSet);
connection.Close();
return dataSet;
}
}
/// <summary>
/// 构建 SqlCommand 对象(用来返回一个结果集，而不是一个整数值)
/// </summary>
/// <param name="connection">数据库连接</param>
/// <param name="storedProcName">存储过程名</param>
/// <param name="parameters">存储过程参数</param>
/// <returns>SqlCommand</returns>
private static SqlCommand BuildQueryCommand(SqlConnection connection,
string storedProcName,
IDataParameter[] parameters)
{
SqlCommand command =
new SqlCommand(storedProcName, connection);
command.CommandType =
CommandType.StoredProcedure;
foreach (SqlParameter parameter
in parameters)
{
command.Parameters.Add(parameter);
}
return command;
}
/// <summary>
/// 执行存储过程，返回影响的行数
/// </summary>
/// <param name="storedProcName">存储过程名</param>
/// <param name="parameters">存储过程参数</param>
/// <param name="rowsAffected">影响的行数</param>
/// <returns></returns>
public static int RunProcedure(
string storedProcName, IDataParameter[] parameters,
out int rowsAffected)
{
using (SqlConnection connection =
new SqlConnection(connectionString))
{
try
{
int result;
connection.Open();
SqlCommand command =
BuildIntCommand(connection, storedProcName, parameters);
rowsAffected =
command.ExecuteNonQuery();
result = (
int)command.Parameters[
"ReturnValue"].Value;
return result;
}
catch (System.Data.SqlClient.SqlException ex)
{
throw new Exception(ex.Message);
}
finally
{
connection.Close();
}
}
}
/// <summary>
/// 构建一个SqlCommand对象(用来返回一个整数值)
/// </summary>
/// <param name="connection">数据库连接</param>
/// <param name="storedProcName">存储过程名</param>
/// <param name="parameters">存储过程参数</param>
private static SqlCommand BuildIntCommand(SqlConnection connection,
string storedProcName,
IDataParameter[] parameters)
{
SqlCommand command =
BuildQueryCommand(connection, storedProcName, parameters);
command.Parameters.Add(new SqlParameter(
"ReturnValue", SqlDbType.Int,
4, ParameterDirection.ReturnValue,
false,
0,
0,
string.Empty, DataRowVersion.Default,
null));
return command;
}
#endregion
#region 执行SQL语句返回受影响行数
/// <summary>
/// 执行SQL语句返回受影响行数
/// </summary>
public static int ExecuteNonQuery(SqlTransaction transaction,
string commandText,
params SqlParameter[] commandParameters)
{
SqlCommand objCommand =
new SqlCommand();
PrepareCommand(objCommand, transaction.Connection, transaction, commandText, commandParameters);
int iNum1 =
objCommand.ExecuteNonQuery();
objCommand.Parameters.Clear();
return iNum1;
}
#endregion
}
C#编程入门--SQLSERVER数据库帮助类
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