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

Question

在 .net 6 項目中使用 EFCore 6.0.8。

當我嘗試加載類的層次結構時，我收到一個異常：Npgsql.PostgreException：'42703' 列 c1.Index 不存在。

我知道我沒有任何名為“c1”的表，而且我認為我的代碼中的任何地方都沒有“索引”列。

注意：經過驗證，我在 EF Core 保留的 class 中有一個“索引”列。

Answer 1

我發現了我的問題。 為了找到它，我將 DbContext 配置為跟蹤 SQL 命令。 然后我直接在 DBeaver 中執行了命令（由 EFCore 構建的命令）（任何 SQL 工具都可以完成這項工作）。

對於鏈接到其他表的查詢，EFCore 使用許多別名來制作 SQL “join”子句（用於關系）。 這些別名首先由一個字母組成，但在它們之后是一個字母+數字。 要發現這些別名，我們必須跟蹤 EFCore 向數據庫發出的請求。 在我的情況下（見下文），表“c1”是用於連接表的別名。

這是我設置“查詢跟蹤”的 DbContext 的 OnConfiguring 的開始：

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

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

我的記錄器：

    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
        }
    }

這是跟蹤 EFCore 的結果。 這是我可以找到我的錯誤的查詢（索引添加字段）。 我沒有添加 linq Qeury 的代碼，因為它是通用查詢的一部分（這是我用來構建查詢的鏈接： 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"