/// <summary>
/// 创建 DELETE 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 TranslateDeleteCommand <T>(DbQueryDeleteTree tree, ITranslateContext context)
{
ISqlBuilder builder = this.CreateSqlBuilder(context);
var typeRuntime = TypeRuntimeInfoCache.GetRuntimeInfo <T>();
builder.Append("DELETE FROM ");
builder.AppendTable(typeRuntime.TableSchema, typeRuntime.TableName, typeRuntime.IsTemporary);
builder.Append(" t0 ");
if (tree.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 = tree.Entity;
builder.AppendNewLine();
builder.Append("WHERE ");
foreach (FieldAccessorBase m in typeRuntime.KeyMembers)
{
var value = m.Invoke(entity);
var sqlExpression = this.Constor.GetSqlValue(value, context, m.Column);
builder.AppendMember("t0", m.Member, typeRuntime.Type);
builder.Append(" = ");
builder.Append(sqlExpression);
builder.Append(" AND ");
}
builder.Length -= 5;
}
else if (tree.Select != null)
{
AliasGenerator ag = this.PrepareTableAlias(tree.Select, context.AliasPrefix);
var cmd = new NpgDbSelectCommand(context, ag, DbExpressionType.Delete, tree.Select.SelectHasMany);
if (tree.Select.Joins != null)
{
var visitor = new NpgJoinExpressionVisitor(ag, cmd.JoinFragment, DbExpressionType.Delete, cmd);
visitor.Visit(tree.Select.Joins);
}
if (tree.Select.Wheres != null)
{
var visitor = new NpgWhereExpressionVisitor(ag, cmd.WhereFragment);
visitor.Visit(tree.Select.Wheres);
cmd.AddNavMembers(visitor.NavMembers);
}
builder.Append(cmd.CommandText);
}
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)
{
ISqlBuilder builder = this.CreateSqlBuilder(context);
var typeRuntime = TypeRuntimeInfoCache.GetRuntimeInfo <T>();
builder.Append("UPDATE ");
builder.AppendTable(typeRuntime.TableSchema, typeRuntime.TableName, typeRuntime.IsTemporary);
builder.Append(" 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;
}
if (m.Column != null && m.Column.IsIdentity)
{
goto LABEL; // Fix issue# 自增列同时又是主键
}
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 T must have key column.");
}
builder.Length = length;
whereBuilder.Length -= 5;
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 NpgUpdateExpressionVisitor(ag, builder);
visitor.Visit(tree.Expression);
var cmd = new NpgDbSelectCommand(context, ag, DbExpressionType.Update, tree.Select.SelectHasMany);
if (tree.Select.Joins != null)
{
visitor = new NpgJoinExpressionVisitor(ag, cmd.JoinFragment, DbExpressionType.Update, cmd);
visitor.Visit(tree.Select.Joins);
}
if (tree.Select.Wheres != null)
{
visitor = new NpgWhereExpressionVisitor(ag, cmd.WhereFragment);
visitor.Visit(tree.Select.Wheres);
cmd.AddNavMembers(visitor.NavMembers);
}
builder.Append(cmd.CommandText);
}
builder.Append(';');
return(new DbRawCommand(builder.ToString(), builder.TranslateContext != null ? builder.TranslateContext.Parameters : null, System.Data.CommandType.Text));
}
