/// <summary> /// Union /// </summary> /// <returns></returns> public static SqlDataReader Union() { //检查 string sql = "select * from BaseTable union select * from Tables"; //不检查 string sql1 = "select * from BaseTable union select * from Tables"; return(SQLHelps.ExecuteReader(sql)); }
/// <summary> /// 连接查询 /// </summary> /// <returns></returns> public static SqlDataReader Join() { //内连接 string sql = "select * from BaseTable join tabname on BaseTable.id=tabname.id"; //左连接 string sql1 = "select * from BaseTable left join tabname on BaseTable.id=tabname.id"; //右连接 string sql2 = "select * from BaseTable right join tabname on BaseTable.id=tabname.id"; //完全外连接 string sql3 = "select * from BaseTable full join tabname on BaseTable.id=tabname.id"; //交叉外连接 string sql4 = "select * from BaseTable cross join tabname "; return(SQLHelps.ExecuteReader(sql)); }
/// <summary> /// 根据条件模糊查询指定表总数 /// </summary> /// <param name="table">查询的表</param> /// <param name="value">条件值</param> /// <returns></returns> public static SqlDataReader SearchLike(string table, string value) { string sql = "select count(*) from " + table + " where name like '%" + value + "%'"; return(SQLHelps.ExecuteReader(sql)); }
/// <summary> /// 查询指定表的数据 /// </summary> /// <param name="table"></param> public static SqlDataReader Search(string table) { string sql = "select count(*) from " + table; return(SQLHelps.ExecuteReader(sql)); }
public static SqlDataReader SearchColumn(string table) { string sql = "select name from syscolumns where id=object_id('" + table + "')"; return(SQLHelps.ExecuteReader(sql)); }
/// <summary> /// 查询数据库所有表名 /// </summary> /// <returns></returns> public static SqlDataReader SearchTable() { string sql = "select name from sysobjects where type='U'"; return(SQLHelps.ExecuteReader(sql)); }
/// <summary> /// Intersect /// </summary> /// <returns></returns> public static SqlDataReader Intersect() { string sql = "select id from BaseTable intersect select id from tabname"; return(SQLHelps.ExecuteReader(sql)); }
/// <summary> /// 查询范围 /// </summary> /// <param name="table">表名</param> /// <param name="column">列名</param> /// <param name="value1">开始值</param> /// <param name="value2">结束值</param> /// <returns></returns> public static SqlDataReader Between(string table, string column, string value1, string value2) { string sql = "select * from " + table + " where " + column + " between " + value1 + " and " + value2; return(SQLHelps.ExecuteReader(sql)); }