sqlite> CREATE VIEW testview AS SELECT * FROM testtable WHERE first_col > 100; 2. 创建临时视图: sqlite> CREATE TEMP VIEW tempview AS SELECT * FROM testtable WHERE first_col > 100; 3. "IF NOT EXISTS"从句: sqlite> CREATE VIEW testview AS SELECT * FROM testtable WHERE first_col > 10...
sqlite> CREATE TEMP VIEW tempview AS SELECT * FROM testtable WHERE first_col > 100; 3). "IF NOT EXISTS"从句: sqlite> CREATE VIEW testview AS SELECT * FROM testtable WHERE first_col > 100; Error: table testview already exists sqlite> CREATE VIEW IF NOT EXISTS testview AS SELECT * FR...
SQLite实现ifnotexist类似功能的操作 需要实现：if not exists(select * from ErrorConfig where Type='RetryWaitSeconds')begin insert into ErrorConfig(Type,Value1)values('RetryWaitSeconds','3')end 只能⽤：insert into ErrorConfig(Type,Value1)select 'RetryWaitSeconds','3'where not exists(select * from...
sqlite> CREATE VIEW IF NOT EXISTS COMPANY_VIEW (VID, VNAME, VAGE) AS ...> SELECT ID, FIRSTNAME, AGE ...> FROM OLD_COMPANY; Run Time: real 0.004 user 0.000252 sys 0.001079 sqlite> SELECT * FROM COMPANY_VIEW; VID VNAME VAGE --- --- --- 1 Paul 32 2 Allen 25 3 Teddy 23 4 ...
CREATEVIEWwatch_singleASSELECTDISTINCTwatch_item.[watchid],watch_item.[itemid]FROMwatch_item; 1. 上面这条SQL语句执行后会显示成功,但是实际上除了 复制 SELECTCOUNT(*)FROM[watch_single ]WHEREwatch_ single.watchid = 1; 1. 能执行之外是无法执行其他任何语句的。其原因在于建立视图的时候指定了字段所在...
create viewifnot exists hn_items_fieldsasselectjson_extract(data,'$.created_at')ascreated_at,json_extract(data,'$.title')astitle,json_extract(data,'$.url')asurl,json_extract(data,'$.author')asauthor,json_extract(data,'$.points')aspoints,json_extract(data,'$.comment_text')ascomment_te...
上述语句规定id为构造表的主键,同时用autoincrement来实现自增长,而后通过not null声明该关键字。 以下为完全的构造语句。 CREATETABLEifnotexistsevents("id"INTEGERPRIMARYKEYAUTOINCREMENTNOTNULL,"name"varchar(32)NOTNULL) 异步操作await的问题: 今天写代码遇到这样一个问题,在进行初始化时,我用return返回这个promise...
1、CREATE TABLE Persons ( Id_P int NOT NULL CHECK (Id_P>0), LastName varchar(255) NOT NULL, FirstName varchar(255), Address varchar(255), City varchar(255) ) 2、CREATE TABLE Persons ( Id_P int NOT NULL, LastName varchar(255) NOT NULL, ...
create table if not exists 表名(字段名1 字段类型1, 字段名2 字段类型2, …) ; 示例 create table t_student (id integer, name text, age inetger, score real) ; 字段类型 SQLite将数据划分为以下几种存储类型: integer : 整型值 real : 浮点值 ...
CREATE VIEW DELETE DETACH DATABASE DROP INDEX DROP TABLE DROP TRIGGER DROP VIEW END TRANSACTION EXPLAIN expression INSERT ON CONFLICT clause PRAGMA REPLACE ROLLBACK TRANSACTION SELECT UPDATE 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. ...