public JoinExpression(Entity entity, WhereExpression where, JoinType jointype)
{
this.Entity = entity;
this.Where = where;
this.JoinType = jointype;
}
/// <summary>
/// 创建更新DbCommand
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="fields"></param>
/// <param name="values"></param>
/// <param name="where"></param>
/// <returns></returns>
public DbCommand CreateUpdateCommand <T>(Field[] fields, object[] values, WhereExpression where)
where T : Entity
{
Guard.Check(!EntityHelper.IsReadOnly <T>(), TextResource.CanNotReadOnly.FormatWith(EntityHelper.GetName <T>()));
if (null == fields || fields.Length == 0 || null == values || values.Length == 0)
{
return(null);
}
Guard.Check(fields.Length == values.Length, TextResource.ArgumentShouldEqual.FormatWith("字段的个数", "值的个数"));
int length = fields.Length;
Field identityField = EntityHelper.GetIdentityField <T>();
bool identityExist = !Field.IsNullOrEmpty(identityField);
if (WhereExpression.IsNullOrEmpty(where))
{
where = WhereExpression.ALL;
}
StringBuilder sql = new StringBuilder();
sql.Append(ExpressionTranslater.SQL_UPDDATE);
sql.Append(db.DbProvider.BuildTableName(EntityHelper.GetName <T>()));
sql.Append(ExpressionTranslater.SQL_UPDATE_SET);
List <QueryParameter> list = new List <QueryParameter>();
StringBuilder colums = new StringBuilder();
var appended = false;
for (int i = 0; i < length; i++)
{
if (identityExist && fields[i].PropertyName.Equals(identityField.PropertyName))
{
continue;
}
if (appended)
{
colums.Append(",");
}
appended = true;
colums.Append(fields[i].FieldName);
colums.Append("=");
if (values[i] is Field)
{
Field fieldValue = (Field)values[i];
colums.Append(fieldValue.FieldNameWithTable);
}
else
{
string pname = CreateParmName();
colums.Append(pname);
var p = new QueryParameter(pname, values[i]);
list.Add(p);
}
}
sql.Append(colums);
var translater = CreateTranslater();
sql.Append(ExpressionTranslater.SQL_WHERE);
translater.SetParmStartIndex(paramCounter);
sql.Append(translater.TranslateWhere(where));
list.AddRange(translater.Params);
DbCommand cmd = db.GetSqlStringCommand(sql.ToString());
db.AddCommandParameter(cmd, list.ToArray());
return(cmd);
}
public JoinExpression(Entity entity, WhereExpression where)
: this(entity, where, JoinType.InnerJoin)
{
}
/// <summary>
/// 创建删除DbCommand
/// </summary>
/// <param name="where"></param>
/// <returns></returns>
public DbCommand CreateDeleteCommand <T>(WhereExpression where)
where T : Entity
{
return(CreateDeleteCommand(EntityHelper.GetName <T>(), where));
}
/// <summary>
/// 翻译查询条件表达式
/// </summary>
/// <param name="exp"></param>
/// <returns></returns>
public string TranslateWhere(WhereExpression exp)
{
StringBuilder str = new StringBuilder();
if (exp.IsSingle)
{
if (exp.Operator == QueryOperator.BitwiseNOT)
{
if (exp.Quote != null && exp.Quote.Operator == QueryOperator.In)
{
return(TranslateWhere(WhereExpression.Create(exp.Quote.LeftField, exp.Quote.Value, QueryOperator.NotIn)));
}
}
if ((exp.LeftField as object) != null && (exp.RightField as object) != null)
{
str.Append(exp.LeftField.FieldNameWithTable);
str.Append(DataHelper.GetOperatorQueryText(exp.Operator));
str.Append(exp.RightField.FieldNameWithTable);
}
else if ((exp.LeftField as object) != null)
{
str.Append(exp.LeftField.FieldNameWithTable);
str.Append(DataHelper.GetOperatorQueryText(exp.Operator));
//子查询 这里只暂时支持写在左边
if (exp.SubExpression != null)
{
str.Append("(" + this.TranslateEntityQuery(exp.SubExpression) + ")");
}
else if (exp.Operator == QueryOperator.In || exp.Operator == QueryOperator.NotIn)
{
str.Append("(");
if (exp.Value != null)
{
var appended = false;
foreach (var value in (IEnumerable)exp.Value)
{
var parm = new QueryParameter(CreateParmName(), value);
this.Params.Add(parm);
if (appended)
{
str.Append(",");
}
str.Append(parm.Name);
appended = true;
}
}
str.Append(")");
}
else if (exp.Operator != QueryOperator.IsNotNULL && exp.Operator != QueryOperator.IsNULL)
{
var parm = new QueryParameter(CreateParmName(), exp.Value);
this.Params.Add(parm);
str.Append(parm.Name);
}
}
else if ((exp.RightField as object) != null)
{
var parm = new QueryParameter(CreateParmName(), exp.Value);
str.Append(parm.Name);
str.Append(DataHelper.GetOperatorQueryText(exp.Operator));
str.Append(exp.RightField.FieldNameWithTable);
this.Params.Add(parm);
}
}
else
{
str.Append("(" + this.TranslateWhere(exp.Left) + ")");
str.Append(DataHelper.GetOperatorQueryText(exp.Operator));
str.Append("(" + this.TranslateWhere(exp.Right) + ")");
}
if (str.Length < 8)
{
return("");
}
return(str.ToString());
}
/// <summary>
/// 查询 更新EntityQueryExpress，并返回 EntityQueryable以便继续操作
/// </summary>
/// <param name="expression"></param>
/// <returns></returns>
public EntityQueryable <T> Where(WhereExpression expression)
{
this.Expression.AddWhere(expression);
return(this);
}
public EntityQueryable <T> Join <TJOIN>(WhereExpression expression)
where TJOIN : Entity
{
return(Join <TJOIN>(expression, JoinType.InnerJoin));
}
public EntityQueryable <T> Having(WhereExpression exp)
{
this.Expression.AddGroupByHaving(exp);
return(this);
}