private void ValidateActionStateChange(DbQueryAction nextAction)
{
if (!CanChangeActionStateTo(nextAction))
{
throw new InvalidOperationException($"不能从当前状态【{m_pLastAction}】变更到【{nextAction}】");
}
}
public void AddUnionAll <TEntity>(DbQuerySet <TEntity> querySet)
{
ValidateActionStateChange(DbQueryAction.SetUnion);
m_pLastAction = DbQueryAction.SetUnion;
this.UnionTargets.Add(new UnionTarget(UnionMode.UnionAll, querySet.QueryContext, this.Session.CreateTempTableName()));
}
public void SetHaving(LambdaExpression havingExpression)
{
ValidateActionStateChange(DbQueryAction.SetHaving);
m_pLastAction = DbQueryAction.SetHaving;
this.HavingExpression = havingExpression;
}
public void SetOrderBy(LambdaExpression orderByExpression)
{
ValidateActionStateChange(DbQueryAction.SetOrderBy);
m_pLastAction = DbQueryAction.SetOrderBy;
this.OrderByExpressions.Add(orderByExpression);
}
public void SetWhere(LambdaExpression whereExpression)
{
ValidateActionStateChange(DbQueryAction.SetWhere);
m_pLastAction = DbQueryAction.SetWhere;
this.WhereExpressions.Add(whereExpression);
}
public void SetGroupBy(LambdaExpression groupByExpression)
{
ValidateActionStateChange(DbQueryAction.SetGroupBy);
m_pLastAction = DbQueryAction.SetGroupBy;
this.GroupByExpression = groupByExpression;
}
public void SetFrom(DbQueryContext queryContext)
{
ValidateActionStateChange(DbQueryAction.SetFrom);
m_pLastAction = DbQueryAction.SetFrom;
this.FromTables.Add(new TableInfo(queryContext, this.Session.CreateTempTableName()));
}
public void SetFrom <TEntity>(DbTable <TEntity> table)
{
ValidateActionStateChange(DbQueryAction.SetFrom);
m_pLastAction = DbQueryAction.SetFrom;
this.FromTables.Add(new TableInfo(table.TableName, this.Session.CreateTempTableName(), typeof(TEntity), table.Schema));
}
public void SetSelect(LambdaExpression selectExpression)
{
ValidateActionStateChange(DbQueryAction.SetSelect);
m_pLastAction = DbQueryAction.SetSelect;
this.SelectExpression = selectExpression;
}
public void SetPaging(uint offset, uint count)
{
ValidateActionStateChange(DbQueryAction.SetPaging);
m_pLastAction = DbQueryAction.SetPaging;
this.PagingInfo = new PagingInfo(offset, count);
}
public void SetDistinct()
{
ValidateActionStateChange(DbQueryAction.SetDistinct);
m_pLastAction = DbQueryAction.SetDistinct;
this.Distinct = true;
}
public void AddLeftJoin <TJoin>(DbQuerySet <TJoin> querySet, LambdaExpression onExpression)
{
ValidateActionStateChange(DbQueryAction.SetJoin);
m_pLastAction = DbQueryAction.SetJoin;
this.FromTables.Add(new TableInfo(querySet.QueryContext, this.Session.CreateTempTableName()));
this.JoinTargets.Add(new JoinTarget(JoinMode.LeftJoin, this.FromTables.Last(), onExpression));
}
public void AddLeftJoin <TJoin>(DbTable <TJoin> table, LambdaExpression onExpression)
{
ValidateActionStateChange(DbQueryAction.SetJoin);
m_pLastAction = DbQueryAction.SetJoin;
this.FromTables.Add(new TableInfo(table.TableName, this.Session.CreateTempTableName(), typeof(TJoin), table.Schema));
this.JoinTargets.Add(new JoinTarget(JoinMode.LeftJoin, this.FromTables.Last(), onExpression));
}
internal DbQueryContext SnapshotForAction(DbQueryAction action)
{
if (!this.CanChangeActionStateTo(action))
{
var newContext = new DbQueryContext(this.Session);
newContext.SetFrom(CloneContext());
return(newContext);
}
return(CloneContext());
}
private bool CanChangeActionStateTo(DbQueryAction nextAction)
{
if (nextAction == DbQueryAction.None)
{
throw new ArgumentException($"参数错误：查询上下文状态错误【{nextAction}】");
}
switch (m_pLastAction)
{
case DbQueryAction.SetFrom:
{
if (nextAction == DbQueryAction.SetJoin ||
nextAction == DbQueryAction.SetWhere ||
nextAction == DbQueryAction.SetGroupBy ||
nextAction == DbQueryAction.SetOrderBy ||
nextAction == DbQueryAction.SetSelect ||
nextAction == DbQueryAction.SetDistinct ||
nextAction == DbQueryAction.SetUnion)
{
return(true);
}
return(false);
}
case DbQueryAction.SetJoin:
{
if (nextAction == DbQueryAction.SetJoin ||
nextAction == DbQueryAction.SetWhere ||
nextAction == DbQueryAction.SetGroupBy ||
nextAction == DbQueryAction.SetOrderBy ||
nextAction == DbQueryAction.SetSelect ||
nextAction == DbQueryAction.SetDistinct)
{
return(true);
}
return(false);
}
case DbQueryAction.SetWhere:
{
if (nextAction == DbQueryAction.SetWhere ||
nextAction == DbQueryAction.SetGroupBy ||
nextAction == DbQueryAction.SetOrderBy ||
nextAction == DbQueryAction.SetSelect ||
nextAction == DbQueryAction.SetDistinct)
{
return(true);
}
if (nextAction == DbQueryAction.SetUnion &&
JoinTargets.Count == 0)
{
return(true);
}
return(false);
}
case DbQueryAction.SetGroupBy:
{
if (nextAction == DbQueryAction.SetHaving ||
nextAction == DbQueryAction.SetOrderBy ||
nextAction == DbQueryAction.SetSelect ||
nextAction == DbQueryAction.SetDistinct)
{
return(true);
}
return(false);
}
case DbQueryAction.SetHaving:
{
if (nextAction == DbQueryAction.SetOrderBy ||
nextAction == DbQueryAction.SetSelect ||
nextAction == DbQueryAction.SetDistinct)
{
return(true);
}
return(false);
}
case DbQueryAction.SetOrderBy:
{
if (nextAction == DbQueryAction.SetOrderBy ||
nextAction == DbQueryAction.SetPaging ||
nextAction == DbQueryAction.SetSelect ||
nextAction == DbQueryAction.SetDistinct)
{
return(true);
}
return(false);
}
case DbQueryAction.SetPaging:
{
if (nextAction == DbQueryAction.SetSelect ||
nextAction == DbQueryAction.SetDistinct)
{
return(true);
}
return(false);
}
case DbQueryAction.SetSelect:
{
if (nextAction == DbQueryAction.SetDistinct ||
nextAction == DbQueryAction.SetUnion)
{
return(true);
}
return(false);
}
case DbQueryAction.SetDistinct:
{
if (nextAction == DbQueryAction.SetUnion)
{
return(true);
}
return(false);
}
case DbQueryAction.SetUnion:
{
if (nextAction == DbQueryAction.SetUnion ||
nextAction == DbQueryAction.SetOrderBy)
{
return(true);
}
return(false);
}
default:
{
if (nextAction == DbQueryAction.SetFrom)
{
return(true);
}
return(false);
}
}
}
