/// <summary>
/// 获取字段存在一列表中的表达式
/// </summary>
/// <param name="value">对象值列表</param>
/// <returns>条件表达式</returns>
public Expression In(IEnumerable <T> values)
{
string p;
int i = 0;
Expression exp = new Expression();
exp.SqlText.Append(" ").Append(Name).Append(" in (");
foreach (object value in values)
{
p = Expression.GetParamName();
if (i > 0)
{
exp.SqlText.Append(",");
}
exp.SqlText.Append("@").Append(p);
exp.Parameters.Add(new Command.Parameter {
Name = p, Value = Mappings.PropertyCastAttribute.CastValue(Table, Name, value)
});
i++;
}
exp.SqlText.Append(" )");
return(exp);
}
/// <summary>
/// 获取字段不等于一个值的表达式
/// </summary>
/// <param name="value">对象值</param>
/// <returns>条件表达式</returns>
public Expression NotEq(T value)
{
Expression exp = new Expression();
string p = Expression.GetParamName();
exp.SqlText.Append(string.Format(" {0}<>@{1} ", Name, p));
exp.Parameters.Add(new Command.Parameter {
Name = p, Value = Mappings.PropertyCastAttribute.CastValue(Table, Name, value)
});
return(exp);
}
/// <summary>
/// 获取字段和另一个表的字段非集条件表达式
/// </summary>
/// <param name="field">并集字段</param>
/// <param name="expression">相应表的条件查询表达式</param>
/// <returns>条件表达式</returns>
public Expression NotIn(FieldInfo <T> field, Expression expression)
{
Expression exp = new Expression();
string astable = "T" + Expression.GetParamName();
exp.SqlText.Append(" ").Append(Name).Append(" not in (select ").Append(astable).Append(".").Append(field.Name).Append(" from ").Append(field.Table).Append(" ").Append(astable);
if (expression != null && expression.SqlText.Length > 0)
{
exp.SqlText.Append(" where ").Append(expression.SqlText.ToString());
exp.Parameters.AddRange(expression.Parameters);
}
exp.SqlText.Append(")");
return(exp);
}
/// <summary>
/// 获取这段不存在指定区间的表达式
/// </summary>
/// <param name="fromvalue">开始值</param>
/// <param name="tovalue">结束值</param>
/// <returns>条件表达式</returns>
public Expression NotBetween(T fromvalue, T tovalue)
{
string p, p1;
Expression exp = new Expression();
p = Expression.GetParamName();
p1 = Expression.GetParamName();
exp.SqlText.Append(string.Format(" {0} not Between @{1} and @{2}", Name, p, p1));
exp.Parameters.Add(new Command.Parameter {
Name = p, Value = Mappings.PropertyCastAttribute.CastValue(Table, Name, fromvalue)
});
exp.Parameters.Add(new Command.Parameter {
Name = p1, Value = Mappings.PropertyCastAttribute.CastValue(Table, Name, tovalue)
});
return(exp);
}
/// <summary>
/// 返回字段匹配某一个值的表达式
/// </summary>
/// <param name="value">值</param>
/// <returns>条件表达式</returns>
public Expression Like(object value)
{
if (value != null && value is System.Collections.IEnumerable && value.GetType() != typeof(string))
{
return(LikeMany((System.Collections.IEnumerable)value));
}
Expression exp = new Expression();
string pn = Expression.GetParamName();
exp.SqlText.Append(
string.Format("{0} like @{1}", Name, pn)
);
exp.Parameters.Add(new Command.Parameter {
Name = pn, Value = Mappings.PropertyCastAttribute.CastValue(Table, Name, value)
});
return(exp);
}
/// <summary>
/// 返回字段匹配相应列表值的表达式,此方法会在值前后添加通配符%
/// </summary>
/// <param name="value">值</param>
/// <returns>条件表达式</returns>
private Expression MatchMany(System.Collections.IEnumerable value)
{
Expression exp = new Expression();
int i = 0;
string pn;
exp.SqlText.Append("(");
foreach (object item in value)
{
pn = Expression.GetParamName();
if (i > 0)
{
exp.SqlText.Append(" or ");
}
exp.SqlText.Append(Name).Append(" like @").Append(pn);
exp.Parameters.Add(new Command.Parameter {
Name = pn, Value = "%" + item + "%"
});
i++;
}
exp.SqlText.Append(")");
return(exp);
}
/// <summary>
/// 返回字段匹配相应列表值的表达式
/// </summary>
/// <param name="value">值</param>
/// <returns>条件表达式</returns>
private Expression LikeMany(System.Collections.IEnumerable value)
{
Expression exp = new Expression();
int i = 0;
string pn;
exp.SqlText.Append("(");
foreach (object item in value)
{
pn = Expression.GetParamName();
if (i > 0)
{
exp.SqlText.Append(" or ");
}
exp.SqlText.Append(Name).Append(" like @").Append(pn);
exp.Parameters.Add(new Command.Parameter {
Name = pn, Value = Mappings.PropertyCastAttribute.CastValue(Table, Name, item)
});
i++;
}
exp.SqlText.Append(")");
return(exp);
}