EF Core 异常：Npgsql.PostgreException：'42703' 列 c1.Index 不存在

Question

在 .net 6 项目中使用 EFCore 6.0.8。

当我尝试加载类的层次结构时，我收到一个异常：Npgsql.PostgreException：'42703' 列 c1.Index 不存在。

我知道我没有任何名为“c1”的表，而且我认为我的代码中的任何地方都没有“索引”列。

注意：经过验证，我在 EF Core 保留的 class 中有一个“索引”列。

Answer 1

我发现了我的问题。 为了找到它，我将 DbContext 配置为跟踪 SQL 命令。 然后我直接在 DBeaver 中执行了命令（由 EFCore 构建的命令）（任何 SQL 工具都可以完成这项工作）。

对于链接到其他表的查询，EFCore 使用许多别名来制作 SQL “join”子句（用于关系）。 这些别名首先由一个字母组成，但在它们之后是一个字母+数字。 要发现这些别名，我们必须跟踪 EFCore 向数据库发出的请求。 在我的情况下（见下文），表“c1”是用于连接表的别名。

这是我设置“查询跟踪”的 DbContext 的 OnConfiguring 的开始：

protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
{
    base.OnConfiguring(optionsBuilder);
    optionsBuilder.EnableSensitiveDataLogging();

    // Trace => Most detailed information
    optionsBuilder.LogTo(DbLogger.WriteLine, Microsoft.Extensions.Logging.LogLevel.Trace);
    ...

我的记录器：

    public class DbLogger
    {
        public Log Log { get; }

        private DbLogger()
        {
            Log = new Log(null, false, null);
            Log.Name = "Ef Core";
            Log.IsAutoSaveOnChange = false;
            Log.IsAutoSaveOnExit = false;
        }

        public static DbLogger Instance { get; } = new DbLogger();

        public static void WriteLine(string ? msg)
        {
            Instance.Log.AddEntry(LogLevel.LogMessage, msg);

#if DEBUG
            Debug.WriteLine($"Database logging: {msg}");
#endif
        }
    }

这是跟踪 EFCore 的结果。 这是我可以找到我的错误的查询（索引添加字段）。 我没有添加 linq Qeury 的代码，因为它是通用查询的一部分（这是我用来构建查询的链接： Entity Framework Core 2.0.1 Eager Loading on all nested related entity ）

  SELECT e."ElectricNetworkId", e."EfficiencyCurveFormula", e."Name", t1."ResourceId", t1."CommConfigId", t1."ElectricNetworkId", t1."Name", t1."GenerationPowerMax", t1."GenerationPowerMin", t1."TimeToCooldown", t1."TimeToStartToFullPower", t1."ActualCapacity", t1."StorageCapacity", t1."MaximumPower", t1."SetPoint", t1."Discriminator", t1."CommConfigId0", t1."CommunicationProtocolType", t1."ResourceId0", t1."Index", t1."IpAddress", t1."Port", t1."Discriminator0", t1."Dnp3PropertyBaseId", t1."CommConfigDnp3Id", t1."Description", t1."Index0", t1."Name0", t1."PropertyName", t1."InputOffset", t1."InputScale", t1."IsPersistent", t1."Offset", t1."OutputControl", t1."Scale", t1."SelectRequired", t1."SmpDeadBand", t1."Unit", t1."UnitMultiplier", t1."InputOffset0", t1."InputScale0", t1."Offset0", t1."OutputControl0", t1."Scale0", t1."SelectRequired0", t1."SmpDeadBand0", t1."Unit0", t1."UnitMultiplier0", t1."Discriminator1"
  FROM "ElectricNetwork" AS e
  LEFT JOIN (
      SELECT r."ResourceId", r."CommConfigId", r."ElectricNetworkId", r."Name", r0."GenerationPowerMax", r0."GenerationPowerMin", r0."TimeToCooldown", r0."TimeToStartToFullPower", r2."ActualCapacity", r2."StorageCapacity", c."MaximumPower", c."SetPoint", CASE
          WHEN (s."ResourceId" IS NOT NULL) THEN 'GazTurbineReadOnly'
          WHEN (b0."ResourceId" IS NOT NULL) THEN 'Battery'
          WHEN (w1."ResourceId" IS NOT NULL) THEN 'WaterHeater'
          WHEN (c."ResourceId" IS NOT NULL) THEN 'ControllableLoad'
          WHEN (w0."ResourceId" IS NOT NULL) THEN 'WindTurbine'
          WHEN (w."ResourceId" IS NOT NULL) THEN 'WaterTurbine'
          WHEN (g."ResourceId" IS NOT NULL) THEN 'GazTurbine'
          WHEN (b."ResourceId" IS NOT NULL) THEN 'Biomass'
      END AS "Discriminator", t."CommConfigId" AS "CommConfigId0", t."CommunicationProtocolType", t."ResourceId" AS "ResourceId0", t."Index", t."IpAddress", t."Port", t."Discriminator" AS "Discriminator0", t0."Dnp3PropertyBaseId", t0."CommConfigDnp3Id", t0."Description", t0."Index" AS "Index0", t0."Name" AS "Name0", t0."PropertyName", t0."InputOffset", t0."InputScale", t0."IsPersistent", t0."Offset", t0."OutputControl", t0."Scale", t0."SelectRequired", t0."SmpDeadBand", t0."Unit", t0."UnitMultiplier", t0."InputOffset0", t0."InputScale0", t0."Offset0", t0."OutputControl0", t0."Scale0", t0."SelectRequired0", t0."SmpDeadBand0", t0."Unit0", t0."UnitMultiplier0", t0."Discriminator" AS "Discriminator1"
      FROM "Resource" AS r
      LEFT JOIN "ResourceGenerator" AS r0 ON r."ResourceId" = r0."ResourceId"
      LEFT JOIN "ResourceStorage" AS r2 ON r."ResourceId" = r2."ResourceId"
      LEFT JOIN "Biomass" AS b ON r."ResourceId" = b."ResourceId"
      LEFT JOIN "GazTurbine" AS g ON r."ResourceId" = g."ResourceId"
      LEFT JOIN "WaterTurbine" AS w ON r."ResourceId" = w."ResourceId"
      LEFT JOIN "WindTurbine" AS w0 ON r."ResourceId" = w0."ResourceId"
      LEFT JOIN "ControllableLoad" AS c ON r."ResourceId" = c."ResourceId"
      LEFT JOIN "WaterHeater" AS w1 ON r."ResourceId" = w1."ResourceId"
      LEFT JOIN "Battery" AS b0 ON r."ResourceId" = b0."ResourceId"
      LEFT JOIN "StorageTestReadOnly" AS s ON r."ResourceId" = s."ResourceId"
      LEFT JOIN (
          SELECT c0."CommConfigId", c0."CommunicationProtocolType", c0."ResourceId", c1."Index", c1."IpAddress", c1."Port", CASE
              WHEN (c1."CommConfigId" IS NOT NULL) THEN 'CommConfigDnp3'
          END AS "Discriminator"
          FROM "CommConfig" AS c0
          LEFT JOIN "CommConfigDnp3" AS c1 ON c0."CommConfigId" = c1."CommConfigId"
      ) AS t ON r."ResourceId" = t."ResourceId"
      LEFT JOIN (
          SELECT d."Dnp3PropertyBaseId", d."CommConfigDnp3Id", d."Description", d."Index", d."Name", d."PropertyName", d0."InputOffset", d0."InputScale", d0."IsPersistent", d0."Offset", d0."OutputControl", d0."Scale", d0."SelectRequired", d0."SmpDeadBand", d0."Unit", d0."UnitMultiplier", d2."InputOffset" AS "InputOffset0", d2."InputScale" AS "InputScale0", d2."Offset" AS "Offset0", d2."OutputControl" AS "OutputControl0", d2."Scale" AS "Scale0", d2."SelectRequired" AS "SelectRequired0", d2."SmpDeadBand" AS "SmpDeadBand0", d2."Unit" AS "Unit0", d2."UnitMultiplier" AS "UnitMultiplier0", CASE
              WHEN (d3."Dnp3PropertyBaseId" IS NOT NULL) THEN 'Dnp3OutputBinary'
              WHEN (d2."Dnp3PropertyBaseId" IS NOT NULL) THEN 'Dnp3OutputAnalog'
              WHEN (d1."Dnp3PropertyBaseId" IS NOT NULL) THEN 'Dnp3InputBinary'
              WHEN (d0."Dnp3PropertyBaseId" IS NOT NULL) THEN 'Dnp3InputAnalog'
          END AS "Discriminator"
          FROM "Dnp3PropertyBase" AS d
          LEFT JOIN "Dnp3InputAnalog" AS d0 ON d."Dnp3PropertyBaseId" = d0."Dnp3PropertyBaseId"
          LEFT JOIN "Dnp3InputBinary" AS d1 ON d."Dnp3PropertyBaseId" = d1."Dnp3PropertyBaseId"
          LEFT JOIN "Dnp3OutputAnalog" AS d2 ON d."Dnp3PropertyBaseId" = d2."Dnp3PropertyBaseId"
          LEFT JOIN "Dnp3OutputBinary" AS d3 ON d."Dnp3PropertyBaseId" = d3."Dnp3PropertyBaseId"
      ) AS t0 ON t."CommConfigId" = t0."CommConfigDnp3Id"
  ) AS t1 ON e."ElectricNetworkId" = t1."ElectricNetworkId"
  ORDER BY e."ElectricNetworkId", t1."ResourceId", t1."CommConfigId0"