/// <summary>
/// 构建lamda表达式的语句
/// </summary>
/// <param name="condition"></param>
/// <param name="column"></param>
/// <returns></returns>
private string GenerateCode(SearchConditionDto condition, ColumnInfo column)
{
var value = condition.Value;
var valuePath = $"o.{column.ValuePath}";
if (column.IsPropertyColumn)
{
//自定义属性列的查询
var dbFuncName = GetDbFunctionName(column.ColumnType);
valuePath = $"MasterDbContext.{dbFuncName}(o.Property,\"$.{column.ColumnKey}\")";
}
if (column.ColumnType != ColumnTypes.Number)
{
value = $"\"{value}\"";
}
if (column.ColumnType == ColumnTypes.DateTime)
{
//日期类型需要转换
value = $"DateTime.Parse({value})";
}
//以.开头的为字符串操作
if (condition.Operator.StartsWith("."))
{
//加括号:a.StartsWith("b")
value = $"({value})";
}
else if (string.IsNullOrEmpty(condition.Value))
{
//非字符串操作，如果未传值，作null处理
value = "null";
}
return($"(o)=>{valuePath}{condition.Operator}{value}");
}
private string GenerateLamdaCode <TEntity>(SearchConditionDto condition, ColumnInfo column, out LambdaExpression dbLamda)
{
dbLamda = null;
var value = condition.Value;
var valuePath = $"{column.ValuePath}";
if (column.IsPropertyColumn)
{
//自定义属性列的查询
//var dbFuncName = GetDbFunctionName(column.ColumnType);
//var p = Expression.Parameter(typeof(TEntity), "x");
//var _pExp = Expression.Constant($"$.{column.ColumnKey}", typeof(string));
//MemberExpression member = Expression.PropertyOrField(p, "Property");
//var expRes = Expression.Call(typeof(TEntity).GetEntityDbContextType().GetMethod(dbFuncName), member, _pExp);
//dbLamda = Expression.Lambda(expRes, p);
dbLamda = GeneratePropertyLamda <TEntity>(column.ColumnType, column.ColumnKey);
//valuePath = $"MasterDbContext.{dbFuncName}(Property,\"$.{column.ColumnKey}\")";
//基于数据库json字段的查询需要动态构建lamda
valuePath = "@0(it)";//@0之后会由dbLamda代入
}
if (column.ColumnType != ColumnTypes.Number)
{
value = $"\"{value}\"";
}
if (column.ColumnType == ColumnTypes.DateTime)
{
//日期类型需要转换
value = $"DateTime.Parse({value})";
}
//以.开头的为字符串操作
if (condition.Operator.StartsWith("."))
{
//加括号:a.StartsWith("b")
value = $"({value})";
}
else if (string.IsNullOrEmpty(condition.Value))
{
//非字符串操作，如果未传值，作null处理
value = "null";
}
return($"{valuePath}{condition.Operator}{value}");
}
