参数化构造的通用查询方法

下面是一个非分页的参数化构造的通用查询方法

        /// <summary>

        /// 参数化查询数据表

        /// </summary>

        /// <param name="dbHelper">数据库连接</param>

        /// <param name="tableName">表明</param>

        /// <param name="parameters">查询的参数</param>

        /// <param name="conditions">查询条件</param>

        /// <param name="topLimit">前多少条</param>

        /// <param name="order">排序</param>

        /// <param name="fields">查询的字段</param>

        /// <returns>数据表</returns>

        public static DataTable GetDataTable(IDbHelper dbHelper, string tableName, List<KeyValuePair<string, object>> parameters, string conditions, int topLimit = 0, string order = null, string fields = " * ")

        {

            string sqlQuery = "SELECT " + fields + " FROM " + tableName;

            string whereSql = string.Empty;

            if (topLimit != 0)

            {

                switch (dbHelper.CurrentDbType)

                {

                    case CurrentDbType.Access:

                    case CurrentDbType.SqlServer:

                        sqlQuery = "SELECT TOP " + topLimit.ToString() + fields + " FROM " + tableName;

                        break;

                    case CurrentDbType.Oracle:

                        whereSql = " ROWNUM < = " + topLimit;

                        break;

                }

            }

            // 要传入 conditions

            if (!string.IsNullOrEmpty(conditions))

            {

                conditions = " WHERE " + conditions;

            }

            sqlQuery += conditions + whereSql;

            if ((order != null) && (order.Length > 0))

            {

                sqlQuery += " ORDER BY " + order;

            }

            var dt = new DataTable(tableName);

            if (topLimit != 0)

            {

                switch (dbHelper.CurrentDbType)

                {

                    case CurrentDbType.MySql:

                        sqlQuery += " LIMIT 0, " + topLimit;

                        break;

                }

            }

            if (parameters != null && parameters.Count > 0)

            {

                dt = dbHelper.Fill(sqlQuery, dbHelper.MakeParameters(parameters));

            }

            else

            {

                dt = dbHelper.Fill(sqlQuery);

            }

            return dt;

        }

 

该方法在吉日通用权限管理的DotNet.Business.DbLogic中可见

调用方法

 

 List<KeyValuePair<string, object>> dbParameters = new List<KeyValuePair<string, object>>();

　　conditions  ....



 DataTable dtResult = CommonManager.GetDataTable(dbHelper, tableName, dbParameters, conditions,0, orderBy, selectField);