/// <summary>
/// 创建 DELETE 命令
/// </summary>
/// <param name="dbQuery">查询语义</param>
/// <param name="token">解析上下文</param>
/// <returns></returns>
protected override RawCommand ResolveDeleteCommand <T>(IDbQueryableInfo_Delete dbQuery, ResolveToken token)
{
var context = (SqlServerDbContext)token.DbContext;
ISqlBuilder builder = this.CreateSqlBuilder(token);
var typeRuntime = TypeRuntimeInfoCache.GetRuntimeInfo <T>();
builder.Append("DELETE t0 FROM ");
builder.AppendMember(typeRuntime.TableName, !typeRuntime.IsTemporary);
builder.Append(" t0 ");
if (dbQuery.Entity != null)
{
if (typeRuntime.KeyMembers == null || typeRuntime.KeyMembers.Count == 0)
{
throw new XFrameworkException("Delete<T>(T value) require entity must have key column.");
}
object entity = dbQuery.Entity;
builder.AppendNewLine();
builder.Append("WHERE ");
foreach (var m in typeRuntime.KeyMembers)
{
var column = m.Column;
var value = m.Invoke(entity);
var seg = this.DbValue.GetSqlValue(value, token, column);
builder.AppendMember("t0", m.Member.Name);
builder.Append(" = ");
builder.Append(seg);
builder.Append(" AND ");
}
builder.Length -= 5;
}
else if (dbQuery.Query != null)
{
TableAlias aliases = this.PrepareTableAlias(dbQuery.Query, token);
var cmd = new SqlServerMappingCommand(context, aliases, token)
{
HasMany = dbQuery.Query.HasMany
};
ExpressionVisitorBase visitor = new SqlServerJoinExpressionVisitor(context, aliases, dbQuery.Query.Joins);
visitor.Write(cmd.JoinFragment);
visitor = new WhereExpressionVisitor(this, aliases, dbQuery.Query.Where);
visitor.Write(cmd.WhereFragment);
cmd.AddNavMembers(visitor.NavMembers);
builder.Append(cmd.CommandText);
}
return(new RawCommand(builder.ToString(), builder.Token != null ? builder.Token.Parameters : null, System.Data.CommandType.Text));
}
/// <summary>
/// 创建 DELETE 命令
/// </summary>
/// <param name="dbQuery">查询语义</param>
/// <param name="token">解析上下文</param>
/// <returns></returns>
protected override RawCommand ResolveDeleteCommand <T>(IDbQueryableInfo_Delete dbQuery, ResolveToken token)
{
ISqlBuilder builder = this.CreateSqlBuilder(token);
var typeRuntime = TypeRuntimeInfoCache.GetRuntimeInfo <T>();
builder.Append("DELETE FROM ");
builder.AppendMember(typeRuntime.TableName, !typeRuntime.IsTemporary);
builder.Append(" ");
if (dbQuery.Entity != null)
{
if (typeRuntime.KeyMembers == null || typeRuntime.KeyMembers.Count == 0)
{
throw new XFrameworkException("Delete<T>(T value) require entity must have key column.");
}
object entity = dbQuery.Entity;
builder.AppendNewLine();
builder.Append("WHERE ");
foreach (var m in typeRuntime.KeyMembers)
{
var column = m.Column;
var value = m.Invoke(entity);
var seg = this.DbValue.GetSqlValue(value, token, column);
builder.AppendMember(m.Member.Name);
builder.Append(" = ");
builder.Append(seg);
builder.Append(" AND ");
}
builder.Length -= 5;
}
else if (dbQuery.Query != null)
{
// 解析查询用来确定是否需要嵌套
var cmd = this.ResolveSelectCommand(dbQuery.Query, 1, false, null) as MappingCommand;
if (token != null && token.Extendsions == null)
{
token.Extendsions = new Dictionary <string, object>();
if (!token.Extendsions.ContainsKey("SQLiteDelete"))
{
token.Extendsions.Add("SQLiteDelete", null);
}
}
if ((cmd.NavMembers != null && cmd.NavMembers.Count > 0) || dbQuery.Query.Joins.Count > 0)
{
// 最外层仅选择 RowID 列
var outQuery = dbQuery.Query;
outQuery.Select = new DbExpression(DbExpressionType.Select, Expression.Constant("t0.RowId", typeof(string)));
var iterator = outQuery;
while (iterator.Subquery != null)
{
var subQuery = new SQLiteDbQueryableInfo_Select(iterator.Subquery);
iterator.Subquery = subQuery;
iterator = subQuery;
}
// 解析成 RowId IN 结构
cmd = (MappingCommand)this.ResolveSelectCommand(dbQuery.Query, 1, false, token);
builder.Append("WHERE ");
builder.AppendMember("RowID");
builder.Append(" IN(");
builder.AppendNewLine(cmd.CommandText);
builder.Append(')');
}
else
{
TableAlias aliases = this.PrepareTableAlias(dbQuery.Query, token);
ExpressionVisitorBase visitor = null;
visitor = new JoinExpressionVisitor(this, aliases, dbQuery.Query.Joins);
visitor.Write(builder);
visitor = new WhereExpressionVisitor(this, null, dbQuery.Query.Where);
visitor.Write(builder);
}
}
builder.Append(';');
return(new RawCommand(builder.ToString(), builder.Token != null ? builder.Token.Parameters : null, System.Data.CommandType.Text));
}
/// <summary> /// 创建 DELETE 命令 /// </summary> /// <param name="dbQuery">查询语义</param> /// <param name="token">解析上下文</param> /// <returns></returns> protected abstract RawCommand ResolveDeleteCommand <T>(IDbQueryableInfo_Delete dbQuery, ResolveToken token);
