//p=>p
//p=>p.t
//p=>p.Id
protected override Expression VisitLambda <T>(Expression <T> node)
{
LambdaExpression lambda = node as LambdaExpression;
if (lambda.Body.NodeType == ExpressionType.Parameter)
{
// 例： a=> a
Type type = lambda.Body.Type;
string alias = _aliases.GetTableAlias(lambda);
this.VisitAllMember(type, alias);
return(node);
}
else if (lambda.Body.CanEvaluate())
{
// 例：a=>1
base.Visit(lambda.Body.Evaluate());
// 选择字段
string newName = AddColumn(_columns, "__Constant__");
// 添加字段别名
_builder.AppendAs(newName);
return(node);
}
else if (lambda.Body.NodeType == ExpressionType.MemberAccess)
{
// 例： t=> t.a
// => SELECT a.ClientId
Type type = lambda.Body.Type;
return(TypeUtils.IsPrimitiveType(type)
? base.VisitLambda(node)
: this.VisitAllMember(type, _aliases.GetTableAlias(lambda.Body), node));
}
return(base.VisitLambda(node));
}
// Cross Join
private void AppendCrossJoin(ISqlBuilder jf, DbExpression exp, TableAliasCache aliases)
{
if (!_appendedKeyword)
{
jf.AppendNewLine();
jf.Append(_keywordName);
_appendedKeyword = true;
}
else
{
jf.Append(',');
jf.AppendNewLine();
jf.Append(" ");
}
LambdaExpression lambdaExp = exp.Expressions[1] as LambdaExpression;
Type type = lambdaExp.Parameters[1].Type;
var typeRuntime = TypeRuntimeInfoCache.GetRuntimeInfo(type);
jf.Append(' ');
jf.AppendMember(typeRuntime.TableName, !typeRuntime.IsTemporary);
string alias = aliases.GetTableAlias(lambdaExp.Parameters[1]);
jf.Append(' ');
jf.Append(alias);
}
/// <summary>
/// 追加列名
/// </summary>
/// <param name="aliases">表别名</param>
/// <param name="expression">列名表达式</param>
/// <returns>返回解析到的表别名</returns>
public string AppendMember(TableAliasCache aliases, Expression expression)
{
Expression exp = expression;
LambdaExpression lambdaExpression = exp as LambdaExpression;
if (lambdaExpression != null)
{
exp = lambdaExpression.Body;
}
if (expression.CanEvaluate())
{
ConstantExpression c = expression.Evaluate();
string value = this.GetSqlValue(c.Value);
_innerBuilder.Append(value);
return(value);
}
else
{
MemberExpression m = expression as MemberExpression;
string alias = aliases == null ? null : aliases.GetTableAlias(m);
this.AppendMember(alias, m.Member.Name);
return(alias);
}
}
// 获取 CROSS JOIN 子句关联表的的别名
private void PrepareCrossJoinAlias(DbExpression exp, TableAliasCache aliases)
{
LambdaExpression lambdaExp = exp.Expressions[1] as LambdaExpression;
for (int index = 0; index < lambdaExp.Parameters.Count; ++index)
{
aliases.GetTableAlias(lambdaExp.Parameters[index]);
}
}
// Cross Join
private void AppendCrossJoin(ISqlBuilder builder, DbExpression exp, TableAliasCache aliases)
{
LambdaExpression lambdaExp = exp.Expressions[1] as LambdaExpression;
Type type = lambdaExp.Parameters[1].Type;
var typeRuntime = TypeRuntimeInfoCache.GetRuntimeInfo(type);
builder.Append(' ');
builder.AppendMember(typeRuntime.TableName, !typeRuntime.IsTemporary);
string alias = aliases.GetTableAlias(lambdaExp.Parameters[1]);
builder.Append(' ');
builder.Append(alias);
builder.Append(' ');
}
// 获取 LEFT JOIN / INNER JOIN 子句关联表的的别名
private void PrepareLfInJoinAlias(DbExpression exp, TableAliasCache aliases)
{
Type type = exp.Expressions[0].Type.GetGenericArguments()[0];
string name = TypeRuntimeInfoCache.GetRuntimeInfo(type).TableName;
// on a.Name equals b.Name 或 on new{ Name = a.Name,Id=a.Id } equals new { Name = b.Name,Id=b.Id }
LambdaExpression left = exp.Expressions[1] as LambdaExpression;
LambdaExpression right = exp.Expressions[2] as LambdaExpression;
if (left.Body.NodeType == ExpressionType.New)
{
NewExpression body1 = left.Body as NewExpression;
NewExpression body2 = right.Body as NewExpression;
for (int index = 0; index < body1.Arguments.Count; ++index)
{
aliases.GetTableAlias(body1.Arguments[index]);
}
for (int index = 0; index < body2.Arguments.Count; ++index)
{
string alias = aliases.GetTableAlias(body2.Arguments[index]);
// 记录显示指定的LEFT JOIN 表别名
aliases.AddOrUpdateJoinTableAlias(name, alias);
}
}
else if (left.Body.NodeType == ExpressionType.MemberInit)
{
MemberInitExpression body1 = left.Body as MemberInitExpression;
MemberInitExpression body2 = right.Body as MemberInitExpression;
for (int index = 0; index < body1.Bindings.Count; ++index)
{
aliases.GetTableAlias((body1.Bindings[index] as MemberAssignment).Expression);
}
for (int index = 0; index < body2.Bindings.Count; ++index)
{
string alias = aliases.GetTableAlias((body2.Bindings[index] as MemberAssignment).Expression);
// 记录显示指定的LEFT JOIN 表别名
aliases.AddOrUpdateJoinTableAlias(name, alias);
}
}
else
{
aliases.GetTableAlias(exp.Expressions[1]);
string alias = aliases.GetTableAlias(exp.Expressions[2]);
// 记录显示指定的LEFT JOIN 表别名
aliases.AddOrUpdateJoinTableAlias(name, alias);
}
}
// 访问导航属性
protected virtual string VisitNavMember(Expression expression, string memberName = null)
{
// 表达式 => b.Client.Address.AddressName
Expression node = expression;
Stack <KeyValuePair <string, MemberExpression> > stack = null;
string alias = string.Empty;
while (node != null && node.Acceptable())
{
if (node.NodeType != ExpressionType.MemberAccess)
{
break;
}
if (stack == null)
{
stack = new Stack <KeyValuePair <string, MemberExpression> >();
}
MemberExpression memberExpression = node as MemberExpression;
TypeRuntimeInfo typeRuntime = TypeRuntimeInfoCache.GetRuntimeInfo(memberExpression.Expression.Type);
ForeignKeyAttribute attribute = typeRuntime.GetInvokerAttribute <ForeignKeyAttribute>(memberExpression.Member.Name);
if (attribute == null)
{
break;
}
string key = memberExpression.GetKeyWidthoutAnonymous();
stack.Push(new KeyValuePair <string, MemberExpression>(key, memberExpression));
node = memberExpression.Expression;
if (node.NodeType == ExpressionType.Call)
{
node = (node as MethodCallExpression).Object;
}
}
if (stack != null && stack.Count > 0)
{
while (stack != null && stack.Count > 0)
{
KeyValuePair <string, MemberExpression> kvp = stack.Pop();
string key = kvp.Key;
MemberExpression m = kvp.Value;
Type type = m.Type;
if (type.IsGenericType)
{
type = type.GetGenericArguments()[0];
}
TypeRuntimeInfo typeRuntime = TypeRuntimeInfoCache.GetRuntimeInfo(type);
// 检查查询表达式是否显示指定该表关联
alias = _aliases.GetJoinTableAlias(typeRuntime.TableName);
if (string.IsNullOrEmpty(alias))
{
// 如果没有，则使用导航属性别名
alias = _aliases.GetNavigationTableAlias(key);
if (!_navMembers.ContainsKey(kvp.Key))
{
_navMembers.Add(kvp);
}
}
// 例： a.Client.ClientId
if (stack.Count == 0 && !string.IsNullOrEmpty(memberName))
{
_builder.AppendMember(alias, memberName);
}
}
}
else
{
// => SelectMany 也会产生类似 'b.Client.Address.AddressName' 这样的表达式
alias = _aliases.GetTableAlias(expression);
_builder.AppendMember(alias, memberName);
}
// fix issue# Join 表达式显式指定导航属性时时，alias 为空
return(alias);
}
// LEFT OR INNER JOIN
private void AppendLfInJoin(ISqlBuilder jf, ISqlBuilder wf, ISqlBuilder on, DbExpression exp, TableAliasCache aliases)
{
bool useExists = false;
LambdaExpression left = exp.Expressions[1] as LambdaExpression;
LambdaExpression right = exp.Expressions[2] as LambdaExpression;
NewExpression body1 = left.Body as NewExpression;
NewExpression body2 = right.Body as NewExpression;
// t0(t1)
string alias = body1 == null
? aliases.GetTableAlias(exp.Expressions[2])
: aliases.GetTableAlias(right.Parameters[0]);//(body2.Arguments[0]);
IDbQueryable sQuery = (IDbQueryable)((exp.Expressions[0] as ConstantExpression).Value);
if (sQuery.DbExpressions.Count == 1 && sQuery.DbExpressions[0].DbExpressionType == DbExpressionType.GetTable)
{
useExists = true;
if ((wf != null && wf.Length > 0) || (on != null && on.Length > 0))
{
wf.AppendNewLine();
if (wf != null && wf.Length > 0)
{
wf.Append("AND ");
}
}
wf.Append("EXISTS(");
wf.Indent += 1;
wf.AppendNewLine();
wf.Append("SELECT 1 FROM ");
Type type = exp.Expressions[0].Type.GetGenericArguments()[0];
var typeRuntime = TypeRuntimeInfoCache.GetRuntimeInfo(type);
wf.AppendMember(typeRuntime.TableName, !typeRuntime.IsTemporary);
wf.Append(' ');
wf.Append(alias);
wf.AppendNewLine();
wf.Append("WHERE ");
}
else
{
useExists = true;
if ((wf != null && wf.Length > 0) || (on != null && on.Length > 0))
{
wf.AppendNewLine();
if (wf != null && wf.Length > 0)
{
wf.Append("AND ");
}
}
wf.Append("EXISTS(");
wf.Indent += 1;
wf.AppendNewLine();
wf.Append("SELECT 1 FROM(");
var cmd2 = sQuery.Resolve(wf.Indent + 1, false, wf.Parameters);
wf.Append(cmd2.CommandText);
wf.AppendNewLine();
wf.Append(')');
wf.Append(' ');
wf.Append(alias);
wf.Append(" WHERE ");
}
ISqlBuilder builder = useExists ? wf : on;
if (body1 == null)
{
builder.AppendMember(aliases, left.Body.ReduceUnary());
builder.Append(" = ");
builder.AppendMember(aliases, right.Body.ReduceUnary());
}
else
{
for (int index = 0; index < body1.Arguments.Count; ++index)
{
builder.AppendMember(aliases, body1.Arguments[index]);
builder.Append(" = ");
builder.AppendMember(aliases, body2.Arguments[index]);
if (index < body1.Arguments.Count - 1)
{
builder.Append(" AND ");
}
}
}
//if (_where != null && _where.Expressions != null) this.AppendWhere(builder, right);
if (useExists)
{
wf.Indent -= 1;
wf.AppendNewLine();
wf.Append(')');
}
}
// LEFT OR INNER JOIN
private void AppendLfInJoin(ISqlBuilder builder, DbExpression exp, TableAliasCache aliases)
{
builder.Append(' ');
IDbQueryable sQuery = (IDbQueryable)((exp.Expressions[0] as ConstantExpression).Value);
if (sQuery.DbExpressions.Count == 1 && sQuery.DbExpressions[0].DbExpressionType == DbExpressionType.GetTable)
{
Type type = exp.Expressions[0].Type.GetGenericArguments()[0];
var typeRuntime = TypeRuntimeInfoCache.GetRuntimeInfo(type);
builder.AppendMember(typeRuntime.TableName, !typeRuntime.IsTemporary);
}
else
{
// 嵌套
var cmd = sQuery.Resolve(builder.Indent + 1, false, builder.Parameters);
builder.Append("(");
builder.AppendNewLine(cmd.CommandText);
builder.Append(')');
}
LambdaExpression left = exp.Expressions[1] as LambdaExpression;
LambdaExpression right = exp.Expressions[2] as LambdaExpression;
// t0(t1)
string alias = !(left.Body.NodeType == ExpressionType.New || left.Body.NodeType == ExpressionType.MemberInit)
? aliases.GetTableAlias(exp.Expressions[2])
: aliases.GetTableAlias(right.Parameters[0]);//(body2.Arguments[0]);
builder.Append(' ');
builder.Append(alias);
builder.Append(' ');
// ON a.Name = b.Name AND a.Id = b.Id
builder.Append("ON ");
if (left.Body.NodeType == ExpressionType.New)
{
NewExpression body1 = left.Body as NewExpression;
NewExpression body2 = right.Body as NewExpression;
for (int index = 0; index < body1.Arguments.Count; ++index)
{
builder.AppendMember(aliases, body1.Arguments[index]);
builder.Append(" = ");
builder.AppendMember(aliases, body2.Arguments[index]);
if (index < body1.Arguments.Count - 1)
{
builder.Append(" AND ");
}
}
}
else if (left.Body.NodeType == ExpressionType.MemberInit)
{
MemberInitExpression body1 = left.Body as MemberInitExpression;
MemberInitExpression body2 = right.Body as MemberInitExpression;
for (int index = 0; index < body1.Bindings.Count; ++index)
{
builder.AppendMember(aliases, (body1.Bindings[index] as MemberAssignment).Expression);
builder.Append(" = ");
builder.AppendMember(aliases, (body2.Bindings[index] as MemberAssignment).Expression);
if (index < body1.Bindings.Count - 1)
{
builder.Append(" AND ");
}
}
}
else
{
builder.AppendMember(aliases, left.Body.ReduceUnary());
builder.Append(" = ");
builder.AppendMember(aliases, right.Body.ReduceUnary());
}
}
// 添加导航属性关联
protected override void AppendNavigation()
{
if (this.NavMembers == null || this.NavMembers.Count == 0)
{
return;
}
// 如果有一对多的导航属性，肯定会产生嵌套查询。那么内层查询别名肯定是t0，所以需要清掉
if (this.HaveListNavigation)
{
_aliases = new TableAliasCache(_aliases.ObviousAlias);
}
//开始产生 USING 子句
ISqlBuilder jf = this.JoinFragment;
int index = -1;
// 未生成USING子句
if (_aliases.ObviousAlias <= 1)
{
jf.AppendNewLine();
jf.Append(_keywordName);
}
else
{
jf.Append(',');
jf.AppendNewLine();
}
foreach (var kvp in this.NavMembers)
{
index++;
string key = kvp.Key;
MemberExpression m = kvp.Value;
TypeRuntimeInfo typeRuntime = TypeRuntimeInfoCache.GetRuntimeInfo(m.Expression.Type);
ForeignKeyAttribute attribute = typeRuntime.GetInvokerAttribute <ForeignKeyAttribute>(m.Member.Name);
string innerKey = string.Empty;
string outerKey = key;
string innerAlias = string.Empty;
if (!m.Expression.Acceptable())
{
innerKey = m.Expression.NodeType == ExpressionType.Parameter
? (m.Expression as ParameterExpression).Name
: (m.Expression as MemberExpression).Member.Name;
}
else
{
MemberExpression mLeft = null;
if (m.Expression.NodeType == ExpressionType.MemberAccess)
{
mLeft = m.Expression as MemberExpression;
}
else if (m.Expression.NodeType == ExpressionType.Call)
{
mLeft = (m.Expression as MethodCallExpression).Object as MemberExpression;
}
string name = TypeRuntimeInfoCache.GetRuntimeInfo(mLeft.Type).TableName;
innerAlias = _aliases.GetJoinTableAlias(name);
if (string.IsNullOrEmpty(innerAlias))
{
string keyLeft = mLeft.GetKeyWidthoutAnonymous();
if (this.NavMembers.ContainsKey(keyLeft))
{
innerKey = keyLeft;
}
}
}
string alias1 = !string.IsNullOrEmpty(innerAlias) ? innerAlias : _aliases.GetTableAlias(innerKey);
string alias2 = _aliases.GetTableAlias(outerKey);
// 补充与USING字符串同等间距的空白
if (_aliases.ObviousAlias > 1 || index > 0)
{
jf.Append(" ");
}
Type type = m.Type;
var typeRumtime2 = TypeRuntimeInfoCache.GetRuntimeInfo(type);
if (type.IsGenericType)
{
type = type.GetGenericArguments()[0];
}
jf.Append(' ');
jf.AppendMember(typeRumtime2.TableName, typeRumtime2.IsTemporary);
jf.Append(' ');
jf.Append(alias2);
if (_onPhrase.Length > 0)
{
_onPhrase.Append(" AND ");
}
for (int i = 0; i < attribute.InnerKeys.Length; i++)
{
_onPhrase.Append(alias1);
_onPhrase.Append('.');
_onPhrase.AppendMember(attribute.InnerKeys[i]);
_onPhrase.Append(" = ");
_onPhrase.Append(alias2);
_onPhrase.Append('.');
_onPhrase.AppendMember(attribute.OuterKeys[i]);
}
if (index < this.NavMembers.Count - 1)
{
jf.Append(',');
jf.AppendNewLine();
}
}
}
// 添加导航属性关联
protected virtual void AppendNavigation()
{
if (this._navMembers == null || this._navMembers.Count == 0)
{
return;
}
// 如果有一对多的导航属性，肯定会产生嵌套查询。那么内层查询别名肯定是t0，所以需要清掉
if (this.HaveListNavigation)
{
_aliases = new TableAliasCache(_aliases.ObviousAlias);
}
//开始产生LEFT JOIN 子句
ISqlBuilder builder = this.JoinFragment;
foreach (var kvp in _navMembers)
{
string key = kvp.Key;
MemberExpression m = kvp.Value;
TypeRuntimeInfo typeRuntime = TypeRuntimeInfoCache.GetRuntimeInfo(m.Expression.Type);
ForeignKeyAttribute attribute = typeRuntime.GetInvokerAttribute <ForeignKeyAttribute>(m.Member.Name);
string innerKey = string.Empty;
string outerKey = key;
string innerAlias = string.Empty;
if (!m.Expression.Acceptable())
{
innerKey = m.Expression.NodeType == ExpressionType.Parameter
? (m.Expression as ParameterExpression).Name
: (m.Expression as MemberExpression).Member.Name;
}
else
{
MemberExpression mLeft = null;
if (m.Expression.NodeType == ExpressionType.MemberAccess)
{
mLeft = m.Expression as MemberExpression;
}
else if (m.Expression.NodeType == ExpressionType.Call)
{
mLeft = (m.Expression as MethodCallExpression).Object as MemberExpression;
}
string name = TypeRuntimeInfoCache.GetRuntimeInfo(mLeft.Type).TableName;
innerAlias = _aliases.GetJoinTableAlias(name);
if (string.IsNullOrEmpty(innerAlias))
{
string keyLeft = mLeft.GetKeyWidthoutAnonymous();
if (_navMembers.ContainsKey(keyLeft))
{
innerKey = keyLeft;
}
}
}
string alias1 = !string.IsNullOrEmpty(innerAlias) ? innerAlias : _aliases.GetTableAlias(innerKey);
string alias2 = _aliases.GetTableAlias(outerKey);
builder.AppendNewLine();
builder.Append("LEFT JOIN ");
Type type = m.Type;
if (type.IsGenericType)
{
type = type.GetGenericArguments()[0];
}
var typeRuntime2 = TypeRuntimeInfoCache.GetRuntimeInfo(type);
builder.AppendMember(typeRuntime2.TableName, !typeRuntime2.IsTemporary);
builder.Append(" ");
builder.Append(alias2);
builder.Append(" ON ");
for (int i = 0; i < attribute.InnerKeys.Length; i++)
{
builder.Append(alias1);
builder.Append('.');
builder.AppendMember(attribute.InnerKeys[i]);
builder.Append(" = ");
builder.Append(alias2);
builder.Append('.');
builder.AppendMember(attribute.OuterKeys[i]);
if (i < attribute.InnerKeys.Length - 1)
{
builder.Append(" AND ");
}
}
}
}