This chapter lists code examples about data maintenance and structure, including INSERT, INSERT FROM SELECT…, DELETE…WHERE…, UPDATE…WHERE…, CREATE/DROP TABLE, ALTER TABLE, KEYS, and CONNECT/DISCONNECT/COMMIT/ROLLBACK.
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A |
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1 |
=demo.query("select * from SCORES") |
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2 |
=A1.insert(0,"Class one",20,"PE",100) |
Append a new record |
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3 |
=A1.insert(5,"Class one",21,"PE",100) |
Insert a new record |
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A |
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1 |
=demo.query("select * from SALES") |
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2 |
=A1.derive() |
Duplicate the table sequence |
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A |
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1 |
=demo.query("select ORDERID,CLIENT,SELLERID, ORDERDATE,AMOUNT from SALES") |
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3 |
=A1.delete(A1.select(AMOUNT<10000)) |
Delete the matching records |
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A |
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=demo.query("select ORDERID,CLIENT,SELLERID, ORDERDATE, AMOUNT from SALES") |
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=A1.select(CLIENT:"HL").run(AMOUNT= int(AMOUNT*1.1)) |
Update data on certain conditions |
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A |
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1 |
=create(ProductNo,ProductName,UnitPrice,Quantity) |
Create a table sequence |
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>A1=null |
Delete the table sequence |
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A |
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=demo.query("select * from EMPLOYEE") |
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2 |
=A1.rename(EID:ID) |
Modify field names |
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A |
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=demo.query("select * from EMPLOYEE") |
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=A1.keys(EID) |
Set a primary key |
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A |
B |
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=connect@e("demo") |
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Establish a connection |
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2 |
>A1.execute@k(...) |
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=A1.error() |
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Error message arising from the execution of the previous database operation |
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if A3==0 |
>A1.commit() |
Commit if no errors |
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else |
>A1.rollback() |
Rollback if any errors occur |
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>A1.close() |
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Close the connection |