protected override Expression Accept(DbExpressionVisitor visitor)
{
return(visitor.VisitLike(this));
}
public override T Accept <T>(DbExpressionVisitor <T> visitor)
{
return(visitor.Visit(this));
}
protected override Expression Accept(DbExpressionVisitor visitor)
{
return(visitor.VisitSqlFunction(this));
}
protected override Expression Accept(DbExpressionVisitor visitor)
{
return(visitor.VisitSqlConstant(this));
}
protected override Expression Accept(DbExpressionVisitor visitor)
{
return(visitor.VisitCommandAggregate(this));
}
protected override Expression Accept(DbExpressionVisitor visitor)
{
return(visitor.VisitSelectRowCount(this));
}
protected override Expression Accept(DbExpressionVisitor visitor)
{
return(visitor.VisitRowNumber(this));
}
protected override Expression Accept(DbExpressionVisitor visitor)
{
return(visitor.VisitChildProjection(this));
}
protected override Expression Accept(DbExpressionVisitor visitor)
{
return(visitor.VisitAggregateRequest(this));
}
protected override Expression Accept(DbExpressionVisitor visitor)
{
return(visitor.VisitIsNotNull(this));
}
/// <summary> /// 创建方法表达式访问器 /// </summary> /// <param name="visitor">表达式访问器</param> /// <returns></returns> protected internal override MethodCallExpressionVisitor CreateMethodCallVisitor(DbExpressionVisitor visitor) => new SQLiteMethodCallExressionVisitor(visitor);
/// <summary>
/// 创建 UPDATE 命令
/// </summary>
/// <param name="tree">查询语义</param>
/// <param name="context">解析SQL命令上下文</param>
/// <returns></returns>
protected override DbRawCommand TranslateUpdateCommand <T>(DbQueryUpdateTree tree, ITranslateContext context)
{
ISqlBuilder builder = this.CreateSqlBuilder(context);
var typeRuntime = TypeRuntimeInfoCache.GetRuntimeInfo <T>();
builder.Append("UPDATE ");
builder.AppendTable(typeRuntime.TableSchema, typeRuntime.TableName, typeRuntime.IsTemporary);
builder.Append(" SET");
builder.AppendNewLine();
if (tree.Entity != null)
{
object entity = tree.Entity;
ISqlBuilder whereBuilder = this.CreateSqlBuilder(context);
bool useKey = false;
int length = 0;
foreach (var item in typeRuntime.Members)
{
var m = item as FieldAccessorBase;
if (m == null || !m.IsDbField)
{
continue;
}
if (m.Column != null && m.Column.IsIdentity)
{
goto LABEL; // Fix issue# 自增列同时又是主键
}
if (m.Column != null && m.Column.DbType is SqlDbType && (SqlDbType)m.Column.DbType == SqlDbType.Timestamp)
{
continue; // 行版本号
}
builder.AppendMember(null, m.Member, typeRuntime.Type);
builder.Append(" = ");
LABEL:
var value = m.Invoke(entity);
var sqlExpression = this.Constor.GetSqlValueWidthDefault(value, context, m.Column);
if (m.Column == null || !m.Column.IsIdentity)
{
builder.Append(sqlExpression);
length = builder.Length;
builder.Append(',');
builder.AppendNewLine();
}
if (m.Column != null && m.Column.IsKey)
{
useKey = true;
whereBuilder.AppendMember(null, m.Member, typeRuntime.Type);
whereBuilder.Append(" = ");
whereBuilder.Append(sqlExpression);
whereBuilder.Append(" AND ");
}
}
if (!useKey)
{
throw new XFrameworkException("Update<T>(T value) require entity must have key column.");
}
builder.Length = length;
whereBuilder.Length -= 5;
builder.AppendNewLine();
builder.Append("WHERE ");
builder.Append(whereBuilder);
}
else if (tree.Expression != null)
{
// SELECT 表达式
LambdaExpression lambda = tree.Expression as LambdaExpression;
var body = lambda.Body;
Expression expression = null;
if (body.NodeType == ExpressionType.MemberInit)
{
var memberInit = body as MemberInitExpression;
var bindings = new List <MemberBinding>(memberInit.Bindings);
foreach (var m in typeRuntime.KeyMembers)
{
var member = Expression.MakeMemberAccess(lambda.Parameters[0], m.Member);
var binding = Expression.Bind(m.Member, member);
if (!bindings.Any(x => x.Member == m.Member))
{
bindings.Add(binding);
}
}
expression = Expression.MemberInit(memberInit.NewExpression, bindings);
}
else if (body.NodeType == ExpressionType.New)
{
var newExpression = body as NewExpression;
var bindings = new List <MemberBinding>();
for (int index = 0; index < newExpression.Members.Count; index++)
{
var m = (FieldAccessorBase)typeRuntime.Members.FirstOrDefault(a => a is FieldAccessorBase && (
a.Name == newExpression.Members[index].Name ||
((FieldAccessorBase)a).Column != null && ((FieldAccessorBase)a).Column.Name == newExpression.Members[index].Name));
if (m == null)
{
throw new XFrameworkException("Member {0}.{1} not found.", typeRuntime.Type.Name, newExpression.Members[index].Name);
}
var binding = Expression.Bind(m.Member, newExpression.Arguments[index].Type != m.CLRType
? Expression.Convert(newExpression.Arguments[index], m.CLRType)
: newExpression.Arguments[index]);
bindings.Add(binding);
}
foreach (var m in typeRuntime.KeyMembers)
{
var member = Expression.MakeMemberAccess(lambda.Parameters[0], m.Member);
var binding = Expression.Bind(m.Member, member);
if (!bindings.Any(x => x.Member == m.Member))
{
bindings.Add(binding);
}
}
var newExpression2 = Expression.New(typeRuntime.Constructor.Member);
expression = Expression.MemberInit(newExpression2, bindings);
}
// 解析查询以确定是否需要嵌套
tree.Select.Select = new DbExpression(DbExpressionType.Select, expression);
var cmd = (DbSelectCommand)this.TranslateSelectCommand(tree.Select, 0, false, this.CreateTranslateContext(context.DbContext));
if ((cmd.NavMembers != null && cmd.NavMembers.Count > 0) || (tree.Select.Joins != null && tree.Select.Joins.Count > 0))
{
if (typeRuntime.KeyMembers == null || typeRuntime.KeyMembers.Count == 0)
{
throw new XFrameworkException("Update<T>(Expression<Func<T, object>> updateExpression) require entity must have key column.");
}
// SET 字段
var visitor = new SQLiteUpdateExpressionVisitor(null, builder, tree, null);
visitor.Translator = this.TranslateSelectCommand;
visitor.Visit(tree.Expression);
// WHERE部分
builder.AppendNewLine();
builder.Append("WHERE EXISTS");
visitor.VisitArgument(tree.Select.Select.Expressions[0], true);
}
else
{
// 直接 SQL 的 UPDATE 语法
DbExpressionVisitor visitor = null;
AliasGenerator ag = this.PrepareTableAlias(tree.Select, context.AliasPrefix);
visitor = new SQLiteUpdateExpressionVisitor(ag, builder, tree, null);
((SQLiteUpdateExpressionVisitor)visitor).Translator = this.TranslateSelectCommand;
visitor.Visit(tree.Expression);
if (tree.Select.Wheres != null)
{
visitor = new WhereExpressionVisitor(null, builder);
visitor.Visit(tree.Select.Wheres);
}
}
}
builder.Append(';');
return(new DbRawCommand(builder.ToString(), builder.TranslateContext != null ? builder.TranslateContext.Parameters : null, System.Data.CommandType.Text));
}
/// <summary>
/// 创建 UPDATE 命令
/// </summary>
/// <param name="tree">查询语义</param>
/// <param name="context">解析SQL命令上下文</param>
/// <returns></returns>
protected override DbRawCommand TranslateUpdateCommand <T>(DbQueryUpdateTree tree, ITranslateContext context)
{
// 增删改不用 NOLOCK
bool noLock = ((SqlServerDbContext)context.DbContext).NoLock;
((SqlServerDbContext)context.DbContext).NoLock = false;
ISqlBuilder builder = this.CreateSqlBuilder(context);
var typeRuntime = TypeRuntimeInfoCache.GetRuntimeInfo <T>();
builder.Append("UPDATE t0 SET");
builder.AppendNewLine();
if (tree.Entity != null)
{
object entity = tree.Entity;
ISqlBuilder whereBuilder = this.CreateSqlBuilder(context);
bool useKey = false;
int length = 0;
foreach (var item in typeRuntime.Members)
{
var m = item as FieldAccessorBase;
if (m == null || !m.IsDbField)
{
continue;
}
// Fix issue# 自增列同时又是主键
if (m.Column != null && m.Column.IsIdentity)
{
goto LABEL;
}
// 忽略行版本号列
if (m.Column != null && m.Column.DbType is SqlDbType && (SqlDbType)m.Column.DbType == SqlDbType.Timestamp)
{
continue;
}
builder.AppendMember("t0", m.Member, typeRuntime.Type);
builder.Append(" = ");
LABEL:
var value = m.Invoke(entity);
var sqlExpression = this.Constor.GetSqlValueWidthDefault(value, context, m.Column);
if (m.Column == null || !m.Column.IsIdentity)
{
builder.Append(sqlExpression);
length = builder.Length;
builder.Append(',');
builder.AppendNewLine();
}
if (m.Column != null && m.Column.IsKey)
{
useKey = true;
whereBuilder.AppendMember("t0", m.Member, typeRuntime.Type);
whereBuilder.Append(" = ");
whereBuilder.Append(sqlExpression);
whereBuilder.Append(" AND ");
}
}
if (!useKey)
{
throw new XFrameworkException("Update<T>(T value) require entity must have key column.");
}
builder.Length = length;
whereBuilder.Length -= 5;
builder.AppendNewLine();
builder.Append("FROM ");
builder.AppendTable(typeRuntime.TableSchema, typeRuntime.TableName, typeRuntime.IsTemporary);
builder.Append(" t0");
builder.AppendNewLine();
builder.Append("WHERE ");
builder.Append(whereBuilder);
}
else if (tree.Expression != null)
{
AliasGenerator ag = this.PrepareTableAlias(tree.Select, context.AliasPrefix);
DbExpressionVisitor visitor = null;
visitor = new UpdateExpressionVisitor(ag, builder);
visitor.Visit(tree.Expression);
builder.AppendNewLine();
builder.Append("FROM ");
builder.AppendTable(typeRuntime.TableSchema, typeRuntime.TableName, typeRuntime.IsTemporary);
builder.AppendAs("t0");
var cmd = new SqlServerDbSelectCommand(context, ag, tree.Select.SelectHasMany);
if (tree.Select.Joins != null)
{
visitor = new SqlServerJoinExpressionVisitor(ag, cmd.JoinFragment);
visitor.Visit(tree.Select.Joins);
}
if (tree.Select.Wheres != null)
{
visitor = new WhereExpressionVisitor(ag, cmd.WhereFragment);
visitor.Visit(tree.Select.Wheres);
cmd.AddNavMembers(visitor.NavMembers);
}
builder.Append(cmd.CommandText);
}
((SqlServerDbContext)context.DbContext).NoLock = noLock;
return(new DbRawCommand(builder.ToString(), builder.TranslateContext != null ? builder.TranslateContext.Parameters : null, System.Data.CommandType.Text));
}
