/// <summary>
/// 访问 IDbQueryable.Contains 方法
/// </summary>
/// <param name="m">字段或属性表达式</param>
protected override Expression VisitQueryableContains(MethodCallExpression m)
{
ITranslateContext context = _builder.TranslateContext;
DbQueryable subquery = m.Arguments[0].Evaluate().Value as DbQueryable;
subquery.Parameterized = _builder.Parameterized;
// 可能会有几级嵌套，这里用 Builder.Ident 标记是第几层级
string[] subs = new[] { "p", "u", "v", "w", "x" };
var newContext = context != null?TranslateContext.Copy(context, subs[_builder.Indent]) : null;
bool isDelete = context != null && ((SQLiteTranslateContext)context).IsDelete;
var cmd = subquery.Translate(_builder.Indent + 1, false, newContext) as DbSelectCommand;
if (this.NotOperands != null && this.NotOperands.Contains(m))
{
_builder.Append("NOT ");
}
_builder.Append("EXISTS(");
_builder.Append(cmd.CommandText);
if (((DbSelectCommand)cmd).WhereFragment.Length > 0)
{
_builder.Append(" AND ");
}
else
{
_builder.Append("WHERE ");
}
_builder.Append(cmd.SelectedColumnText);
_builder.Append(" = ");
// exists 不能用别名
if (isDelete)
{
var typeRuntime = TypeRuntimeInfoCache.GetRuntimeInfo(((MemberExpression)m.Arguments[1]).Expression.Type);
_builder.AppendTable(typeRuntime.TableSchema, typeRuntime.TableName, typeRuntime.IsTemporary);
_builder.Append('.');
}
_visitor.Visit(m.Arguments[1]);
_builder.Append(")");
return(m);
}
/// <summary>
/// 解析 SQL 命令
/// <para>
/// 返回的已经解析语义中执行批次用 null 分开
/// </para>
/// </summary>
/// <param name="dbQueryables">查询语句</param>
/// <returns></returns>
public override List <DbRawCommand> Translate(List <object> dbQueryables)
{
bool haveBegin = false;
ITranslateContext context = null;
var sqlList = new List <DbRawCommand>();
for (int i = 0; i < dbQueryables.Count; i++)
{
object obj = dbQueryables[i];
if (obj == null)
{
continue;
}
if (obj is IDbQueryable)
{
DbQueryable dbQuery = (DbQueryable)obj;
dbQuery.Parameterized = true;
if (context == null)
{
context = this.CreateTranslateContext(dbQuery.DbContext);
}
if (context.Parameters == null)
{
context.Parameters = new List <IDbDataParameter>(8);
}
var cmd = dbQuery.Translate(0, true, context);
if (cmd is DbSelectCommand)
{
// 查询单独执行
if (sqlList.Count > 0 && (i - 1) >= 0 && sqlList[sqlList.Count - 1] != null)
{
sqlList.Add(null);
}
sqlList.Add(cmd);
sqlList.Add(null);
context = this.CreateTranslateContext(dbQuery.DbContext);
context.Parameters = new List <IDbDataParameter>(8);
}
else
{
// 增删改
if (!haveBegin)
{
sqlList.Add(new DbRawCommand("BEGIN"));
haveBegin = true;
}
sqlList.Add(cmd);
if (cmd.Parameters != null && cmd.Parameters.Count > 1000)
{
// 1000个参数，就要重新分批
if (haveBegin)
{
sqlList.Add(new DbRawCommand("END;"));
haveBegin = false;
sqlList.Add(null);
}
context = this.CreateTranslateContext(dbQuery.DbContext);
context.Parameters = new List <IDbDataParameter>(8);
}
if (i + 1 < dbQueryables.Count)
{
// 检查下一条是否是选择语句
bool isQuery = false;
if (dbQueryables[i + 1] is IDbQueryable)
{
var tree = ((DbQueryable)dbQueryables[i + 1]).Parse();
isQuery = tree is DbQuerySelectTree;
}
else if ((dbQueryables[i + 1] is string))
{
string sql = dbQueryables[i + 1].ToString();
string method = string.Empty;
if (sql.Length > 6)
{
method = sql.Substring(0, 6).Trim().ToUpper();
}
isQuery = method == "SELECT";
}
else if (dbQueryables[i + 1] is DbRawSql)
{
string sql = ((DbRawSql)dbQueryables[i + 1]).CommandText;
string method = string.Empty;
if (sql.Length > 6)
{
method = sql.Substring(0, 6).Trim().ToUpper();
}
isQuery = method == "SELECT";
}
// 如果下一条是SELECT 语句，则需要结束当前语句块
if (isQuery)
{
if (haveBegin)
{
sqlList.Add(new DbRawCommand("END;"));
haveBegin = false;
sqlList.Add(null);
}
context = this.CreateTranslateContext(dbQuery.DbContext);
context.Parameters = new List <IDbDataParameter>(8);
}
}
}
}
else if (obj is DbRawSql || obj is string)
{
string sql = string.Empty;
if (obj is string)
{
sql = obj.ToString();
}
else
{
DbRawSql rawSql = (DbRawSql)obj;
// 解析参数
object[] args = null;
if (rawSql.Parameters != null)
{
args = rawSql.Parameters.Select(x => this.Constor.GetSqlValue(x, context)).ToArray();
}
sql = rawSql.CommandText;
if (args != null && args.Length > 0)
{
sql = string.Format(sql, args);
}
}
string methodName = string.Empty;
if (sql.Length > 6)
{
methodName = sql.Substring(0, 6).Trim().ToUpper();
}
if (methodName == "SELECT")
{
if (sqlList.Count > 0 && (i - 1) >= 0 && sqlList[sqlList.Count - 1] != null)
{
sqlList.Add(null);
}
}
var cmd = new DbRawCommand(sql, context.Parameters, CommandType.Text);
sqlList.Add(cmd);
if (methodName == "SELECT")
{
sqlList.Add(cmd);
sqlList.Add(null);
context = this.CreateTranslateContext(obj is DbRawSql ? ((DbRawSql)obj).DbContext : null);
context.Parameters = new List <IDbDataParameter>(8);
}
else if (cmd.Parameters != null && cmd.Parameters.Count > 1000)
{
// 1000个参数，就要重新分批
if (haveBegin)
{
sqlList.Add(new DbRawCommand("END;"));
sqlList.Add(null);
haveBegin = false;
}
context = this.CreateTranslateContext(obj is DbRawSql ? ((DbRawSql)obj).DbContext : null);
context.Parameters = new List <IDbDataParameter>(8);
}
}
else
{
if (!haveBegin)
{
sqlList.Add(new DbRawCommand("BEGIN"));
haveBegin = true;
}
// 解析批量插入操作
List <IDbQueryable> bulkList = obj as List <IDbQueryable>;
if (bulkList != null && bulkList.Count > 0)
{
this.TranslateBulk(sqlList, bulkList);
}
}
if (haveBegin && i == dbQueryables.Count - 1)
{
sqlList.Add(new DbRawCommand("END;"));
}
}
return(sqlList);
}