使用 group by 并加入 sequelize

Question

我在 PostgreSQL 数据库中有两个表，contracts 和 payments。一份合同已完成多次付款。

我有以下两个模型：

 module.exports = function(sequelize, DataTypes) {
  var contracts = sequelize.define('contracts', {
    id: {
      type: DataTypes.INTEGER,
      autoIncrement: true
    }
  }, {
    createdAt: false,
    updatedAt: false,
    classMethods: {
      associate: function(models) {
        contracts.hasMany(models.payments, {
          foreignKey: 'contract_id'
        });
      }
    }
  });


  return contracts;
};

module.exports = function(sequelize, DataTypes) {
  var payments = sequelize.define('payments', {
    id: {
      type: DataTypes.INTEGER,
      autoIncrement: true
    },
    contract_id: {
      type: DataTypes.INTEGER,
    },
    payment_amount: DataTypes.INTEGER,
  }, {
    classMethods: {
      associate: function(models) {
        payments.belongsTo(models.contracts, {
          foreignKey: 'contract_id'
        });
      }
    }
  });


  return payments;
};

我想对每个合同的所有付款进行求和，并使用了这个函数：

models.contracts.findAll({
    attributes: [
        'id'
    ],
    include: [
    {
        model: models.payments,
        attributes: [[models.sequelize.fn('sum', models.sequelize.col('payments.payment_amount')), 'total_cost']]
    }
    ],
    group: ['contracts.id']
})

但它生成以下查询：

SELECT "contracts"."id", "payments"."id" AS "payments.id", sum("payments"."payment_amount") AS "payments.total_cost" 
FROM "contracts" AS "contracts" 
LEFT OUTER JOIN "payments" AS "payments" ON "contracts"."id" = "payments"."contract_id" GROUP BY "contracts"."id";

我不要求 select payments.id，因为我必须将其包含在我的聚合或按函数分组中，如我的错误所述：

Possibly unhandled SequelizeDatabaseError: error: column "payments.id" must appear in the GROUP BY clause or be used in an aggregate function

我是不是漏掉了什么？我正在关注 this answer，但即使在那里我也不明白 SQL 请求如何有效。

Answer 1

您可能希望从 payments 中选择问题并加入 contracts 而不是相反？

Answer 2

你能把你的函数写成

models.contracts.findAll({
    attributes: [
        'models.contracts.id'
    ],
    include: [
    {
        model: models.payments,
        attributes: [[models.sequelize.fn('sum', models.sequelize.col('payments.payment_amount')), 'total_cost']]
    }
    ],
    group: ['contracts.id']
})

Answer 3

尝试

group: ['contracts.id', 'payments.id']

Answer 4

此问题已在 Sequelize 3.0.1 上修复，包含模型的主键必须用

排除

attributes: []

并且聚合必须在主模型上完成（this github issue 中的信息）。

因此对于我的用例，代码如下

models.contracts.findAll({
    attributes: ['id', [models.sequelize.fn('sum', models.sequelize.col('payments.payment_amount')), 'total_cost']],
    include: [
    {
        model: models.payments,
        attributes: []
    }
    ],
    group: ['contracts.id']
})

使用 group by 并加入 sequelize

Using group by and joins in sequelize

sql

postgresql

node.js

sequelize.js