Question

从错误中我认为这是Npgsql（see closed issue）的问题，但错误是使用OrmLite Select＆lt;＆gt;因为它改变了执行的sql。

问题：

除了不使用WITH CTE之外，OrmLite还有另一种解决此错误的方法吗？
是db.Select＆lt;＆gt;要使用错误的命令？

注意：WITH CTE适用于OrmLite.Scalar

Postgres WITH CTE：http://www.postgresql.org/docs/current/static/queries-with.html

更新：问题似乎是OrmLite准备SQL语句而不是以＆＃34; SELECT＆＃34;开头。导致OrmLite将SQL视为＆＃34; WHERE＆＃34; PARAM。

[Test]
public void with_cte_ormlite_obj()
{
    using (var db = DbConnection)
    {
        var sql = "WITH w_cnt AS (SELECT 5 AS cnt, 'me' AS name) SELECT cnt, name FROM w_cnt";

// An exception of type 'Npgsql.NpgsqlException' occurred in Npgsql.dll
// ERROR: 42601: syntax error at or near "WITH w_cnt"
// Actual Exec Sql: 
// SELECT "cnt", "name" FROM "my_with_cte_obj" WHERE WITH w_cnt AS (SELECT 5 AS cnt, 'me' AS name) SELECT cnt, name FROM w_cnt

        var cnt = db.Select<MyWithCteObj>(sql);
        var first = cnt.First();
        Assert.AreEqual(5, first.Cnt);
        Assert.AreEqual("me", first.Name);
    }
}

public class MyWithCteObj
{
    public int Cnt { get; set; }
    public string Name { get; set; }
}

Answer 1

db.Select<T>() API只能用于SQL SELECT 语句。

db.SqlList<T>() API应该用于非SELECT查询，例如：

using (var db = DbConnection)
{
    var cnt = db.SqlList<MyWithCteObj>(
        "WITH w_cnt AS (SELECT 5 AS cnt, 'me' AS name) SELECT cnt, name FROM w_cnt");
}

请参阅文档了解更多custom SQL APIs examples。

ServiceStack.OrmLite选择＆lt;＆gt;使用WITH CTE时抛出npgsql语法错误

1 个答案: