/// <summary>
/// 生成where命令。
/// </summary>
/// <param name="expression">带格式串的表达式。</param>
/// <param name="value">值，忽略null和string.Empty。</param>
/// <param name="operator">逻辑操作符。</param>
/// <param name="valueFilter">值过虑器，value不为null或string.Empty时。</param>
/// <returns></returns>
public virtual ISelectCommandBuilder WhereIf(string expression, object value, WhereOperators @operator, WhereIfValueFilterDelegate <object> valueFilter = null)
{
_whereExpression?.WhereIf(expression, value, @operator, valueFilter);
return(this);
}
/// <summary>
/// 生成where命令。
/// </summary>
/// <param name="expression">带格式串的表达式。</param>
/// <param name="value">值，忽略null和string.Empty。</param>
/// <param name="operator">逻辑操作符。</param>
/// <param name="valueFilter">值过虑器，value不为null或string.Empty时。</param>
/// <returns></returns>
public virtual IWhereExpression WhereIf(string expression, object value, WhereOperators @operator, WhereIfValueFilterDelegate <object> valueFilter = null)
{
if (!string.IsNullOrEmpty(expression) && value != null)
{
if (value is string && string.IsNullOrEmpty((string)value))
{
return(this);
}
return(Where(@operator, string.Format(expression, AddCommandParameter(valueFilter == null ? value : valueFilter(value)))));
}
return(this);
}
/// <summary>
/// 生成where命令。
/// </summary>
/// <param name="expression">带格式串的表达式。</param>
/// <param name="value">值，忽略null和string.Empty。</param>
/// <param name="op">逻辑操作符：and、or，不区分大小写。</param>
/// <param name="valueFilter">值过虑器，value不为null或string.Empty时。</param>
/// <returns></returns>
public virtual ISelectCommandBuilder WhereIf(string expression, object value, string op = "and", WhereIfValueFilterDelegate <object> valueFilter = null)
{
_whereExpression?.WhereIf(expression, value, op, valueFilter);
return(this);
}
/// <summary>
/// 生成where命令。
/// </summary>
/// <param name="expression">带格式串的表达式。</param>
/// <param name="value">值，忽略null和string.Empty。</param>
/// <param name="op">逻辑操作符：and、or，不区分大小写。</param>
/// <param name="valueFilter">值过虑器，value不为null或string.Empty时。</param>
/// <returns></returns>
public virtual IWhereExpression WhereIf(string expression, string value, string op = "and", WhereIfValueFilterDelegate <string> valueFilter = null)
{
if (!string.IsNullOrEmpty(expression) && !string.IsNullOrEmpty(value))
{
return(Where(string.Format(expression, AddCommandParameter(valueFilter == null ? value : valueFilter(value))), op));
}
return(this);
}