// 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>
/// 初始化 <see cref="JoinExpressionVisitor"/> 类的新实例
/// </summary>
public JoinExpressionVisitor(IDbQueryProvider provider, TableAliasCache aliases, List <DbExpression> qJoin)
: base(provider, aliases, null, false)
{
_qJoin = qJoin;
_aliases = aliases;
_provider = provider;
}
/// <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);
}
}
/// <summary>
/// 实例化 <see cref="Builder" /> 的新实例
/// </summary>
public OracleDeleteDbCommandDefinition(IDbQueryProvider provider, TableAliasCache aliases, List <IDbDataParameter> parameters)
: base(provider, aliases, parameters)
{
_provider = provider;
_aliases = aliases;
_onPhrase = _provider.CreateSqlBuilder(parameters);
}
/// <summary>
/// 初始化 <see cref="OracleJoinExpressionVisitor"/> 类的新实例
/// </summary>
public OracleJoinExpressionVisitor(IDbQueryProvider provider, TableAliasCache aliases, List <DbExpression> qJoin, DbExpression qWhere)
: base(provider, aliases, null, false)
{
_provider = provider;
_qJoin = qJoin;
_aliases = aliases;
_where = qWhere;
}
/// <summary>
/// 初始化 <see cref="ExpressionVisitorBase"/> 类的新实例
/// </summary>
public ExpressionVisitorBase(IDbQueryProvider provider, TableAliasCache aliases, Expression exp, bool useNominate = true)
{
_provider = provider;
_aliases = aliases;
_expression = exp;
_visitedMember = new VisitedMemberList();
_navMembers = new Dictionary <string, MemberExpression>();
}
// 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]);
}
}
/// <summary>
/// 初始化 <see cref="StatisExpressionVisitor"/> 类的新实例
/// </summary>
public StatisExpressionVisitor(IDbQueryProvider provider, TableAliasCache aliases, DbExpression statis, DbExpression groupBy = null, string alias = null)
: base(provider, aliases, statis.Expressions != null ? statis.Expressions[0] : null, false)
{
_provider = provider;
_aliases = aliases;
_statis = statis;
_groupBy = groupBy;
_alias = alias;
}
/// <summary>
/// 初始化 <see cref="OrderByExpressionVisitor"/> 类的新实例
/// </summary>
public OrderByExpressionVisitor(IDbQueryProvider provider, TableAliasCache aliases, List <DbExpression> qOrder, DbExpression groupBy = null, string alias = null)
: base(provider, aliases, null, false)
{
_qOrder = qOrder;
_aliases = aliases;
_groupBy = groupBy;
_alias = alias;
_provider = provider;
}
/// <summary>
/// 实例化 <see cref="SelectDbCommandDefinition"/> 类的新实例
/// </summary>
/// <param name="provider">数据查询提供者</param>
/// <param name="aliases">别名</param>
/// <param name="parameters">已存在的参数列表</param>
public SelectDbCommandDefinition(IDbQueryProvider provider, TableAliasCache aliases, List <IDbDataParameter> parameters)
: base(string.Empty, null, System.Data.CommandType.Text)
{
_provider = provider;
_aliases = aliases;
_navMembers = new Dictionary <string, MemberExpression>();
_joinFragment = provider.CreateSqlBuilder(parameters);
_whereFragment = provider.CreateSqlBuilder(parameters);
}
/// <summary>
/// 根据指定表达式取表别名
/// </summary>
/// <param name="exp">表达式</param>
/// <remarks>
/// t=>t.Id
/// t.Id
/// </remarks>
public string GetTableAlias(Expression exp)
{
// p=>p.p
// p=>p.Id
// p=>p.t.Id
// p.Id
// p.t.Id
// p.t
// <>h__TransparentIdentifier0.p.Id
XFrameworkException.Check.NotNull(exp, "exp");
string key = TableAliasCache.GetTableAliasKey(exp);
return(this.GetTableAlias(key));
}
private static string GetTableAliasKey(Expression exp)
{
if (exp == null)
{
return(null);
}
Expression expression = exp.ReduceUnary();
//c
if (exp.CanEvaluate())
{
return(null);
}
// p
ParameterExpression paramExp = expression as ParameterExpression;
if (paramExp != null)
{
return(paramExp.Name);
}
// a=>a.Id
LambdaExpression lambdaExp = expression as LambdaExpression;
if (lambdaExp != null)
{
expression = lambdaExp.Body.ReduceUnary();
}
// a.Id
// t.a
// t.t.a
// t.a.Id
MemberExpression memExp = expression as MemberExpression;
if (memExp == null)
{
return(TableAliasCache.GetTableAliasKey(expression));
}
if (memExp.Acceptable())
{
return(TableAliasCache.GetTableAliasKey(memExp.Expression));
}
return(memExp.Member.Name);
}
// 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(' ');
}
/// <summary>
/// 初始化 <see cref="JoinExpressionVisitor"/> 类的新实例
/// </summary>
public NpgJoinExpressionVisitor(IDbQueryProvider provider, TableAliasCache aliases, List <DbExpression> qJoin, NpgCommandType operationType)
: base(provider, aliases, null, false)
{
_qJoin = qJoin;
_aliases = aliases;
_operationType = operationType;
if (_operationType == NpgCommandType.DELETE)
{
_keywordName = "USING";
}
else if (_operationType == NpgCommandType.UPDATE)
{
_keywordName = "FROM";
}
}
// 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);
}
}
/// <summary>
/// 初始化 <see cref="ColumnExpressionVisitor"/> 类的新实例
/// </summary>
public ColumnExpressionVisitor(IDbQueryProvider provider, TableAliasCache aliases, IDbQueryableInfo_Select qQuery)
: base(provider, aliases, qQuery.Select.Expressions != null ? qQuery.Select.Expressions[0] : null)
{
_provider = provider;
_aliases = aliases;
_qQuery = qQuery;
_groupBy = qQuery.GroupBy;
_include = qQuery.Include;
if (_columns == null)
{
_columns = new Dictionary <string, Column>();
}
_navigations = new NavigationCollection();
_navChainHopper = new List <string>(10);
_visitedNavigations = new Dictionary <string, string>(8);
}
/// <summary>
/// 实例化 <see cref="Builder" /> 的新实例
/// </summary>
public NpgDeleteDbCommandDefinition(IDbQueryProvider provider, TableAliasCache aliases, NpgCommandType operationType, List <IDbDataParameter> parameters)
: base(provider, aliases, parameters)
{
_provider = provider;
_aliases = aliases;
_onPhrase = _provider.CreateSqlBuilder(parameters);
_operationType = operationType;
if (_operationType == NpgCommandType.DELETE)
{
_keywordName = "USING";
}
else if (_operationType == NpgCommandType.UPDATE)
{
_keywordName = "FROM";
}
}
// 获取 JOIN 子句关联表的的别名
protected TableAliasCache PrepareAlias <T>(DbQueryableInfo_Select <T> query)
{
TableAliasCache aliases = new TableAliasCache((query.Join != null ? query.Join.Count : 0) + 1);
foreach (DbExpression exp in query.Join)
{
// [INNER/LEFT JOIN]
if (exp.DbExpressionType == DbExpressionType.GroupJoin || exp.DbExpressionType == DbExpressionType.Join || exp.DbExpressionType == DbExpressionType.GroupRightJoin)
{
this.PrepareLfInJoinAlias(exp, aliases);
}
else if (exp.DbExpressionType == DbExpressionType.SelectMany)
{
this.PrepareCrossJoinAlias(exp, aliases);
}
}
return(aliases);
}
/// <summary>
/// 初始化 <see cref="NpgWhereExpressionVisitor"/> 类的新实例
/// </summary>
public NpgWhereExpressionVisitor(IDbQueryProvider provider, TableAliasCache aliases, DbExpression exp)
: base(provider, aliases, exp)
{
_expression = exp != null && exp.Expressions != null ? exp.Expressions[0] : null;
}
// 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();
}
}
}
/// <summary>
/// 初始化 <see cref="HavingExpressionVisitor"/> 类的新实例
/// </summary>
public HavingExpressionVisitor(IDbQueryProvider provider, TableAliasCache aliases, DbExpression having, DbExpression groupBy)
: base(provider, aliases, having != null && having.Expressions != null ? having.Expressions[0] : null)
{
_groupBy = groupBy;
_aliases = aliases;
}
// 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(')');
}
}
// Cross Join
private void AppendCrossJoin(ISqlBuilder jf, DbExpression exp, TableAliasCache aliases)
{
throw new NotSupportedException("Oracle not support.");
}
// 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 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 ");
}
}
}
}
/// <summary>
/// 初始化 <see cref="NpgUpdateExpressionVisitor"/> 类的新实例
/// </summary>
public NpgUpdateExpressionVisitor(IDbQueryProvider provider, TableAliasCache aliases, Expression exp)
: base(provider, aliases, exp)
{
_provider = provider;
_aliases = aliases;
}
/// <summary>
/// 追加列名
/// </summary>
/// <param name="expression">列名表达式</param>
/// <param name="aliases">表别名</param>
/// <returns>返回解析到的表别名</returns>
public Expression AppendMember(Expression expression, TableAliasCache aliases)
{
this.AppendMember(aliases, expression);
return(expression);
}
/// <summary>
/// 初始化 <see cref="GroupByExpressionVisitor"/> 类的新实例
/// </summary>
public GroupByExpressionVisitor(IDbQueryProvider provider, TableAliasCache aliases, DbExpression groupBy)
: base(provider, aliases, groupBy != null ? groupBy.Expressions[0] : null, false)
{
}