초생 wrote:

> 테이블 자동생성을 하는데 secondary indexes생성은 어떻게하는지 예제좀...



DBE 디렉토리의 localsql.hlp을 참조하세요

아래는 그 내용입니다.



Creates a secondary index.



CREATE [UNIQUE] [ASC | DESC] INDEX index_reference ON table_reference (column_reference [,column_reference...])



Description



Use the CREATE INDEX statement to create a secondary index for an existing table. Index names may not have embedded spaces. Paradox indexes may be based on multiple columns. Due to the distinctive nature of dBASE expression indexes, only single-column indexes can be created with CREATE INDEX.



Use UNIQUE to create an index that raises an error if rows with duplicate column values are inserted. By default, indexes are not unique.



Use ASC (or ASCENDING) to create an index that orders data in an ascending direction (smallest to largest). DESC (or DESCENDING) creates a descending ordering (largest to smallest). When a direction imperative is not specified, ASC is the implied default.



The following statement creates a multi-column (compound) Paradox secondary index.



CREATE INDEX custdate ON "orders.db" (custno, saledate)



The following statement creates a unique dBASE secondary index.



CREATE UNIQUE INDEX namex ON "employee.dbf" (last_name)



The existence of indexes may affect the updatability of queries. See the section on updatable queries for more information.

너무어렵네요...

설명좀..

초생 wrote:

> 너무어렵네요...

> 설명좀..

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예를 들어

테이블명 : insa

인덱스할 필드명 : name

인덱스명 : nx_name

이라할 때 2차 인덱스 생성 방법은 다음과 같습니다.



create index nx_name on insa(name) //일반적인 키생성

create unique index nx_name on insa(name) //이름필드를 유일키로(중복불허)

create desc index nx_name on insa(name) //이름필드를 역순으로 인덱스

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도움이 되었으면 좋겠습니다.

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