/// <summary>
/// 创建不等于条件表达式
/// </summary>
/// <param name="fieldname">左边字段名称</param>
/// <param name="parametname">右边参数名称</param>
/// <param name="parametvalue">右边参数值</param>
/// <param name="paramet">返回与条件表达式一起使用的参数表达式</param>
/// <returns></returns>
internal static string CreateNotEqWhere(
string fieldname,
string parametname,
object parametvalue,
out IDataParamet paramet)
{
paramet = null;
if (string.IsNullOrEmpty(fieldname) || string.IsNullOrEmpty(parametname))
{
return(null);
}
string left = fieldname;
if (MsSqlServerHelper.IsValidFieldName(fieldname))
{
left = MsSqlServerHelper.GetFeildNameInSqlExpress(fieldname);
}
if (parametvalue == null)
{
return(string.Format("{0} IS NOT NULL", left));
}
string right = MsSqlServerHelper.GetParametName(parametname);
paramet = new DataParamet()
{
Direction = System.Data.ParameterDirection.Input, Name = parametname, Value = parametvalue, ValueType = parametvalue.GetType()
};
return(string.Format("{0}<>{1}", left, right));
}
/// <summary>
/// 合并条件表达式为或者表达式
/// </summary>
/// <param name="wheres">表达式数组</param>
/// <param name="paramets">表达式参数数组</param>
/// <param name="rtparamets">合并后的表达式参数数组</param>
/// <returns>或者表达式</returns>
internal static string UnionWhereForOr(
IEnumerable <string> wheres,
IEnumerable <IDataParamet> paramets,
out IEnumerable <IDataParamet> rtparamets)
{
rtparamets = null;
if (paramets != null)
{
List <IDataParamet> rt = new List <IDataParamet>();
foreach (var a in paramets)
{
if (rt.FirstOrDefault(f => string.Equals(MsSqlServerHelper.GetParametName(f.Name), MsSqlServerHelper.GetParametName(a.Name), StringComparison.OrdinalIgnoreCase)) == null)
{
rt.Add(a);
}
}
if (rt.Count > 0)
{
rtparamets = rt.ToArray();
}
}
if (wheres != null)
{
StringBuilder xb = new StringBuilder();
foreach (var s in wheres)
{
if (xb.Length == 0)
{
xb.AppendFormat("({0})", s);
}
else
{
xb.AppendFormat(" OR ({0})", s);
}
}
return(xb.ToString());
}
return(null);
}
/// <summary>
/// 创建以parametvalue开始或在parametvalue中以列的值开始的条件表达式
/// </summary>
/// <param name="fieldname">列字段名称</param>
/// <param name="parametname">参数名称</param>
/// <param name="parametvalue">参数值</param>
/// <param name="parametIsExpress">是否是取在parametvalue中以列的值开始的条件表达式</param>
/// <param name="paramet"></param>
/// <returns></returns>
internal static string CreateFirstIndexOfWhere(
string fieldname,
string parametname,
string parametvalue,
bool parametIsExpress,
out IDataParamet paramet)
{
paramet = null;
if (string.IsNullOrEmpty(fieldname) || string.IsNullOrEmpty(parametname))
{
return(null);
}
string left = fieldname;
if (MsSqlServerHelper.IsValidFieldName(fieldname))
{
left = MsSqlServerHelper.GetFeildNameInSqlExpress(fieldname);
}
if (parametvalue == null)
{
return(null);
}
string right = MsSqlServerHelper.GetParametName(parametname);
paramet = new DataParamet()
{
Direction = System.Data.ParameterDirection.Input, Name = parametname, Value = parametvalue, ValueType = parametvalue.GetType()
};
if (parametIsExpress)
{
return(string.Format("CHARINDEX({1},{0})=1", left, right));
}
else
{
return(string.Format("CHARINDEX({0},{1})=1", left, right));
}
}