该类的核心代码
///<summary>/// 私有化构造器(单例模式开发数据库查询工具类) ///</summary>private SqlServerHelper() { } ///<summary>/// 程序执行前实例化一个数据库帮助类 ///</summary>privatestaticSqlServerHelper sqlServer =
new SqlServerHelper(); ///<summary>/// 数据库连接字符串 ///</summary>privatestring connection; ///<summary>/// 数据库命令执行方法(SQL语句) ///</summary>privateintCommand(
string sql) { SqlConnection conn=
new SqlConnection(connection); try { SqlCommand command=
new SqlCommand(sql, conn); conn.Open(); return command.ExecuteNonQuery(); } catch { return0; } finally { conn.Close(); } } ///<summary>/// 查询(SQL语句) ///</summary>privateDataTable GetList(
string sql) { SqlConnection conn=
new SqlConnection(connection); try { SqlDataAdapter adapter=
new SqlDataAdapter(sql, conn); DataTable data=
new DataTable(); adapter.Fill(data); return data; } catch (Exception ex) { thrownew Exception(ex.Message); } } #endregion///<summary>/// 创建该单例类的方法(数据库连接字符串) ///</summary>publicstaticSqlServerHelper GetSqlServer(
string connection) { sqlServer.connection=
connection; return sqlServer; } ///<summary>/// 完全查询(表名, 字段) //表名和字段最好加上中括号[Id] ///</summary>publicDataTable GetList(
stringtableName,
string field) { stringsql =
string.Format(
"select {0} from {1}", field, tableName); return GetList(sql); } ///<summary>/// 条件查询(表名, 字段, 条件) ///</summary>publicDataTable GetList(
stringtableName,
stringfield,
stringwhere) { stringsql =
string.Format(
"select {0} form {1} where {2}", field, tableName,
where); return GetList(sql); } ///<summary>/// 分页查询(表名, 字段, 条件, 主键, 页码, 条数) ///</summary>publicDataTable GetList(
stringtableName,
stringfield,
stringwhere,
stringidField,
intpage,
int size) { stringsql =
string.Format(
"select top {0} {1} from {2} where {3} not in (select top {4} {5} from {6} where {7}) and ({8})", size, field, tableName, idField, (page-
1) * size, idField, tableName,
where,
where ); return GetList(sql); } ///<summary>/// 排序查询(表名, 字段, 条件, 排序) ///</summary>publicDataTable GetList(
stringtableName,
stringfield,
stringwhere,
string order) { stringsql =
string.Format(
"select {0} form {1} where {2} order by {3}", field, tableName,
where, order); return GetList(sql); } ///<summary>/// 分页排序查询(表名, 字段, 条件, 主键, 页码, 条数, 排序) ///</summary>publicDataTable GetList(
stringtableName,
stringfield,
stringwhere,
stringidField,
intpage,
intsize,
string order) { stringsql =
string.Format(
"select top {0} {1} from {2} where {3} not in (select top {4} {5} from {6} where {7}) and ({8}) order by {9}", size, field, tableName, idField, (page-
1) * size, idField, tableName,
where,
where, order ); return GetList(sql); } ///<summary>/// 条件删除(表名, 条件) //返回受影响的行数, 0 表示失败 ///</summary>publicintDelete(
stringtableName,
stringwhere) { stringsql =
string.Format(
"delete from {0} where {1}", tableName,
where); return Command(sql); } ///<summary>/// 条件修改(表名, 更新的数据, 条件) ///</summary>publicintUpdate(
stringtableName,
stringupdateData,
stringwhere) { stringsql =
string.Format(
"update {0} set {1} where {2}", tableName, updateData,
where); return Command(sql); } } }来源: http://www.bubuko.com/infodetail-1958955.html