Entity Framework Core，执行原始 SQL 并参数化表名

Question

我正在使用 Entity Framework Core，当我运行以下查询时，它一切都按预期工作，并从 flasher_equipment 表中选择所有实体。

public async Task<IEnumerable<BaseEquipmentType>> GetNewAvailableEquipment(string tableName)
{
    DbSet<BaseEquipmentType> dbSet = _context.Set<BaseEquipmentType>();
    IQueryable<BaseEquipmentType> types = dbSet.FromSql($"select * from flasher_equipment");
    return await types.ToArrayAsync();
}

但现在，我不想硬编码表名 (flasher_equipment)，而是想将其作为参数传递。

我已尝试将代码更改如下：

public async Task<IEnumerable<BaseEquipmentType>> GetNewAvailableEquipment(string tableName)
{
    DbSet<BaseEquipmentType> dbSet = _context.Set<BaseEquipmentType>();
    IQueryable<BaseEquipmentType> types = dbSet.FromSql($"select * from {tableName}");
    return await types.ToArrayAsync();
}

我也试过了

public async Task<IEnumerable<BaseEquipmentType>> GetNewAvailableEquipment(string tableName)
{
    DbSet<BaseEquipmentType> dbSet = _context.Set<BaseEquipmentType>();
    IQueryable<BaseEquipmentType> types = dbSet.FromSql("select * from {0}", tableName);
    return await types.ToArrayAsync();
}

每次出现错误时：

Grpc.AspNetCore.Server.ServerCallHandler[6]
执行服务方法“GetByPlanIdAnImplementation”时出错。 Oracle.ManagedDataAccess.Client.OracleException (0x80004005): ORA-00903: 无效的表名

为什么将表名参数化为参数导致它崩溃？

Answer 1

好像是FromSqlmethod with the string interpolation的问题。

如果您在方法外部插入字符串，它可能会起作用，如：

public async Task<IEnumerable<BaseEquipmentType>> GetNewAvailableEquipment(string tableName)
{
    DbSet<BaseEquipmentType> dbSet = _context.Set<BaseEquipmentType>();
    string sqlStatement = $"select * from {tableName}"; 
    IQueryable<BaseEquipmentType> types = dbSet.FromSql(sqlStatement);
    return await types.ToArrayAsync();
}