在 postgresql 中创建视图

Question

我在 PostgreSQL 数据库中有几个表和两个函数。 我将 SQL Server 数据库迁移到 PostgreSQL 数据库。 现在，我想创建一个从多个表中获取数据的视图。 这在 SQL Server 中可以正常工作，但在 PostgreSQL 中却不行，因为它具有不同的架构和语法。 有谁知道如何在 PostgreSQL 中创建视图？ 如何将 SQL Server 视图转换为 PostgreSQL？ 我是 PostgreSQL 新手，对它了解不多。 所以，这是我的"payment_status" 查看代码

 ALTER VIEW "PAYMENT_STATUS" AS 
SELECT        dbo.PAYMENTS.ID, dbo.PAYMENTS.ACADEMIC_YEAR, dbo.PAYMENTS.BRANCH, dbo.PAYMENTS.MEMBER_ID, dbo.STUDENTS.FULL_NAME, dbo.STUDENTS.MOBILE, dbo.STUDENTS.EMAIL, dbo.PAYMENTS.STD, 
                         dbo.PAYMENTS.FEE_TYPE, dbo.PAYMENTS.INSTALLMENT, dbo.PAYMENTS.AMOUNT, dbo.PAYMENTS.LATE_FEE_RATE, dbo.PAYMENTS.LATE_FEE_LIMIT, dbo.PAYMENTS.START_DATE, dbo.PAYMENTS.DUE_DATE, 
                         dbo.PAYMENTS.EXPIRY_DATE, dbo.PAYMENTS.REMARKS, ISNULL(TRANSACTIONS.ID, - 1) AS TXID, ISNULL(TRANSACTIONS.TXN_ID, '') AS TXN_ID, ISNULL(TRANSACTIONS.TXN_DATE, '') AS TXN_DATE, 
                         ISNULL(TRANSACTIONS.TOTAL_AMOUNT, dbo.PAYMENTS.AMOUNT + dbo.CalcDue(dbo.PAYMENTS.DUE_DATE, dbo.PAYMENTS.LATE_FEE_RATE, dbo.PAYMENTS.LATE_FEE_LIMIT)) AS TOTAL_AMOUNT, 
                         ISNULL(TRANSACTIONS.TOTAL_LATE_FEE_AMOUNT, dbo.CalcDue(dbo.PAYMENTS.DUE_DATE, dbo.PAYMENTS.LATE_FEE_RATE, dbo.PAYMENTS.LATE_FEE_LIMIT)) AS TOTAL_LATE_FEE_AMOUNT, 
                         ISNULL(TRANSACTIONS.PAYMENT_MODE, '') AS PAYMENT_MODE, ISNULL(TRANSACTIONS.REF_NO, '') AS REF_NO, ISNULL(TRANSACTIONS.REF_DETAILS, '') AS REF_DETAILS, 
                         ISNULL(TRANSACTIONS.TECH_RESPONSE_F1, '') AS TECH_RESPONSE_F1, ISNULL(TRANSACTIONS.TECH_RESPONSE_F2, '') AS TECH_RESPONSE_F2, ISNULL(TRANSACTIONS.REMARKS, '') AS TX_REMARKS, 
                         ISNULL(TRANSACTIONS.STATUS, 'DUE') AS STATUS, ISNULL(TRANSACTIONS.FINANCIAL_INSTITUTE, '') AS FINANCIAL_INSTITUTE, ISNULL(TRANSACTIONS.CREATED_BY, dbo.PAYMENTS.CREATED_BY) 
                         AS TX_CREATED_BY, ISNULL(TRANSACTIONS.CREATED_ON, dbo.PAYMENTS.CREATED_ON) AS TX_CREATED_ON, ISNULL(TRANSACTIONS.MODIFIED_BY, dbo.PAYMENTS.MODIFIED_BY) AS TX_MODIFIED_BY, 
                         ISNULL(TRANSACTIONS.MODIFIED_ON, dbo.PAYMENTS.MODIFIED_ON) AS TX_MODIFIED_ON, dbo.PAYMENTS.CREATED_BY, dbo.PAYMENTS.CREATED_ON, dbo.PAYMENTS.MODIFIED_BY, 
                         dbo.PAYMENTS.MODIFIED_ON , ISNULL(TRANSACTIONS.ERPStatus, '') AS TX_ERPStatus
FROM            dbo.PAYMENTS INNER JOIN
                         dbo.STUDENTS ON dbo.PAYMENTS.MEMBER_ID = dbo.STUDENTS.MEMBER_ID LEFT OUTER JOIN
                         (SELECT * FROM dbo.TRANSACTIONS WHERE STATUS!='REVERSED') AS TRANSACTIONS ON dbo.PAYMENTS.ID = TRANSACTIONS.PAYMENT_ID ;

Answer 1

最后，我得到了解决方案，这就是我在 postgresql 中创建视图的方式。

CREATE or REPLACE VIEW "payment_status" AS  SELECT payments.id,
payments.academic_year,
payments.branch,
payments.member_id,
students.full_name,
students.mobile,
students.email,
payments.std,
payments.fee_type,
payments.installment,
payments.amount,
payments.late_fee_rate,
payments.late_fee_limit,
payments.start_date,
payments.due_date,
payments.expiry_date,
payments.remarks,
COALESCE(transactions.id, ('-1'::integer)::bigint) AS txid,
COALESCE(transactions.txn_id, ''::text) AS txn_id,
COALESCE(transactions.txn_date, (NULL::date)::timestamp with time zone) AS txn_date,
COALESCE(transactions.total_amount, (payments.amount + calc_due((payments.due_date)::date, payments.late_fee_rate, payments.late_fee_limit))) AS total_amount,
COALESCE(transactions.total_late_fee_amount, calc_due((payments.due_date)::date, payments.late_fee_rate, payments.late_fee_limit)) AS total_late_fee_amount,
COALESCE(transactions.payment_mode, ''::text) AS payment_mode,
COALESCE(transactions.ref_no, ''::text) AS ref_no,
COALESCE(transactions.ref_details, ''::text) AS ref_details,
COALESCE(transactions.tech_response_f1, ''::text) AS tech_response_f1,
COALESCE(transactions.tech_response_f2, ''::text) AS tech_response_f2,
COALESCE(transactions.remarks, ''::text) AS tx_remarks,
COALESCE(transactions.status, 'DUE'::text) AS status,
COALESCE(transactions.financial_institute, ''::text) AS financial_institute,
COALESCE(transactions.created_by, payments.created_by) AS tx_created_by,
COALESCE(transactions.created_on, payments.created_on) AS tx_created_on,
COALESCE(transactions.modified_by, payments.modified_by) AS tx_modified_by,
COALESCE(transactions.modified_on, payments.modified_on) AS tx_modified_on,
payments.created_by,
payments.created_on,
payments.modified_by,
payments.modified_on,
COALESCE(transactions.erpstatus, ''::text) AS tx_erpstatus
FROM ((payments
 JOIN students ON ((payments.member_id = students.member_id)))
 LEFT JOIN ( SELECT transactions_1.id,
        transactions_1.txn_id,
        transactions_1.txn_date,
        transactions_1.payment_id,
        transactions_1.total_amount,
        transactions_1.total_late_fee_amount,
        transactions_1.payment_mode,
        transactions_1.ref_no,
        transactions_1.ref_details,
        transactions_1.tech_response_f1,
        transactions_1.tech_response_f2,
        transactions_1.remarks,
        transactions_1.status,
        transactions_1.financial_institute,
        transactions_1.created_by,
        transactions_1.created_on,
        transactions_1.modified_by,
        transactions_1.modified_on,
        transactions_1.erpstatus
       FROM transactions transactions_1
      WHERE (transactions_1.status <> 'REVERSED'::text)) transactions ON ((payments.id = transactions.payment_id))); ;