/// <summary>
/// 将表达式所表示的SQL片断写入 SQL 生成器
/// </summary>
/// <param name="builder">SQL 语句生成器</param>
/// <param name="newLine">表示是否需要强制换行</param>
public void Write(ISqlBuilder builder, bool newLine)
{
if (_orderBy.Count > 0)
{
base._builder = builder;
if (base._methodVisitor == null)
{
base._methodVisitor = _provider.CreateMethodVisitor(this);
}
if (newLine)
{
_builder.AppendNewLine();
}
_builder.Append("ORDER BY ");
for (int i = 0; i < _orderBy.Count; i++)
{
this.VisitWithoutRemark(x => this.Visit(_orderBy[i].Expressions[0]));
if (_orderBy[i].DbExpressionType == DbExpressionType.OrderByDescending || _orderBy[i].DbExpressionType == DbExpressionType.ThenByDescending)
{
builder.Append(" DESC");
}
if (i < _orderBy.Count - 1)
{
builder.Append(',');
}
}
}
}
/// <summary>
/// 写入SQL片断
/// </summary>
public override void Write(ISqlBuilder builder)
{
base._builder = builder;
if (base._methodVisitor == null)
{
base._methodVisitor = _provider.CreateMethodVisitor(this);
}
foreach (DbExpression qj in _qJoin)
{
builder.AppendNewLine();
// [INNER/LEFT JOIN]
if (qj.DbExpressionType == DbExpressionType.GroupJoin || qj.DbExpressionType == DbExpressionType.Join || qj.DbExpressionType == DbExpressionType.GroupRightJoin)
{
JoinType joinType = JoinType.InnerJoin;
if (qj.DbExpressionType == DbExpressionType.GroupJoin)
{
joinType = JoinType.LeftJoin;
}
else if (qj.DbExpressionType == DbExpressionType.GroupRightJoin)
{
joinType = JoinType.RightJoin;
}
this.AppendJoinType(builder, joinType);
this.AppendLfInJoin(builder, qj, _aliases);
}
else if (qj.DbExpressionType == DbExpressionType.SelectMany)
{
this.AppendJoinType(builder, JoinType.CrossJoin);
this.AppendCrossJoin(builder, qj, _aliases);
}
}
}
/// <summary>
/// 写入SQL片断
/// </summary>
public void Write(NpgNavigationCommand cmd)
{
ISqlBuilder jf = cmd.JoinFragment;
ISqlBuilder on = cmd.OnPhrase;
base._builder = on;
if (base._methodVisitor == null)
{
base._methodVisitor = _provider.CreateMethodVisitor(this);
}
if (_qJoin != null && _qJoin.Count > 0)
{
for (int i = 0; i < _qJoin.Count; i++)
{
DbExpression qj = _qJoin[i];
if (qj.DbExpressionType == DbExpressionType.GroupJoin || qj.DbExpressionType == DbExpressionType.Join || qj.DbExpressionType == DbExpressionType.GroupRightJoin)
{
this.AppendLfInJoin(jf, on, qj, _aliases);
}
else if (qj.DbExpressionType == DbExpressionType.SelectMany)
{
this.AppendCrossJoin(jf, qj, _aliases);
}
}
}
}
/// <summary>
/// 将表达式所表示的SQL片断写入SQL构造器
/// </summary>
public override void Write(ISqlBuilder builder)
{
if (base.Expression != null)
{
base._builder = builder;
_builder.AppendNewLine();
_startLength = _builder.Length;
if (base._methodVisitor == null)
{
base._methodVisitor = _provider.CreateMethodVisitor(this);
}
// SELECT 表达式解析
if (base.Expression.NodeType != ExpressionType.Constant)
{
base.Write(builder);
}
else
{
// if have no select syntax
Type type = (base.Expression as ConstantExpression).Value as Type;
this.VisitAllMember(type, "t0");
}
// Include 表达式解析<导航属性>
this.VisitInclude();
// 去掉空白字符
_builder.TrimEnd(' ', ',');
}
}
/// <summary>
/// 将表达式所表示的SQL片断写入SQL构造器
/// </summary>
/// <param name="builder">SQL 语句生成器</param>
public override void Write(ISqlBuilder builder)
{
base._builder = builder;
if (base._methodVisitor == null)
{
base._methodVisitor = _provider.CreateMethodVisitor(this);
}
if (_aggregate != null)
{
Expression exp = _aggregate.DbExpressionType == DbExpressionType.Count ? Expression.Constant(1) : base.Expression;
if (exp.NodeType == ExpressionType.Lambda)
{
exp = (exp as LambdaExpression).Body;
}
// q.Average(a => a);
// 这种情况下g.Key 一定是单个字段，否则解析出来的SQL执行不了
if (exp.NodeType == ExpressionType.Parameter)
{
exp = _groupBy.Expressions[0];
}
builder.Append(_aggregateMethods[_aggregate.DbExpressionType]);
builder.Append("(");
base.Visit(exp);
builder.Append(")");
}
}
/// <summary>
/// 将表达式所表示的SQL片断写入SQL构造器
/// </summary>
/// <param name="builder">SQL 语句生成器</param>
public virtual void Write(ISqlBuilder builder)
{
_builder = builder;
if (_methodVisitor == null)
{
_methodVisitor = _provider.CreateMethodVisitor(this);
}
if (_expression != null)
{
this.Visit(_expression);
}
}