sqlite | 易学教程

How to return the value of AUTO INCREMENT column in SQLite with VB6

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问题 I have a table in SQLite: CREATE TABLE "EventType" ( [EventTypeID] INTEGER PRIMARY KEY, [EventTypeName] VARCHAR(50) NOT NULL UNIQUE ); Since EventTypeID is an integer and a primary key, that automatically makes it an auto-incrementing column, and that works fine. I'd like to insert a row into the table and get the newly incremented value from VB6. Dim oRs as Recordset dim oCmd as new Command oCmd.ActiveConnection = GetConnection() oCmd.Source = "insert into EventType (EventTypeName) values (

How to return the value of AUTO INCREMENT column in SQLite with VB6

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sqlite主键与唯一约束

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主键和约束键概念 RIMARY KEY：设置主键 unique：唯一约束 CREATE TABLE IF NOT EXISTS manager ( id INTEGER PRIMARY KEY AUTOINCREMENT ,title text unique,field_department text,field_email text,field_image text, field_telephone text ) ; 一、主键惟一地标识一行(一张表中只能有一个主键) 主键应当是对用户没有意义的（常用于索引）永远不要更新主键，否则违反对用户没有意义原则主键不应包含动态变化的数据，如时间戳、创建时间列、修改时间列等在两个表的关系中，主关键字用来在一个表中引用来自于另一个表中的特定记录语法： create table 表名称 (列名称1 数据类型 primary key, 列名称2 数据类型,列名称3 数据类型, …); 二、唯一约束用来保证一个列（或一组列）中数据唯一，类似于主键，但跟主键有区别表可包含多个唯一约束，但只允许一个主键唯一约束列可修改或更新创建表时，通过unique来设置语法: create table 表名 (列名称1 数据类型 unique，列名称2 数据类型 ,…。); 来源： CSDN 作者： Mr_WoLong 链接： https:/

SQLiteBlobTooBigException still occurs after dividing the request in chunks of 1 MB (and cursor.close())

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问题 It is possible to import a text file of 6MB directly into my database. However, the text can't be extracted since CursorWindow has a limit of 2MB. (I should have used files, but some users already have this problem and I would need to read the entire text to be able to put it in a file) I used substr (a special SQL function) to only request 1 MB and it worked. However, the following while loop doesn't work after the second iteration (which means that even if I called cursor.close(), the

How to insert date in sqlite through java

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问题 I want to make a database that will hold a date in it(SQLite). Now first to ask is what is the right syntax to declare a date column. The second i want to know is how to insert date in it after that. And the third thing i want to know is how to select dates between, for example to select all rows which contain date between 01/05/2010 and 05/06/2010. Thank you 回答1: Now first to ask is what is the right syntax to declare a date column. From the SQLite Data Types documentation: 1.2 Date and Time

SQLite附加数据库(ATTACH DATABASE)

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在开发过程中，经常需要多个表之间进行操作。对于同一个数据库来说，相互之间连接表，容易实现。但是对于不同的数据库，使用Sqlite该怎么实现呢？针对这种需要不同数据库之间的表连接操作的情况，SQLite提供了一种将外部数据库附加到当前数据库连接的机制——ATTACH DATABASE。这里我们有俩张测试表，company和userinfo ，其中表Company放在Study.db库中，表userinfo放在Userinfo.db 中表：company（Study.db）表userinfo（Userinfo.db）可以看到表company中有一条的数据，表Userinfo中有俩条数据，而且其中都包含相同的ID=> 2,假设我们要找出company和userifo中相同的数据，进行表关联。那么请继续往下看首先看看各自所在库中包含的表有哪些，使用.tables命令库：Study.db 库：Userinfo.db 而后使用命令attach database 将Study.db附加到Userinfo.db中可以看到附加成功，而且Userinfo.db中也能看到Study.db中的表了接下来就可以写SQL了 OK！来源： CSDN 作者：嗯，干得漂亮链接： https://blog.csdn.net/HobbyFull/article/details/104028881

SQLite: Obtaining total of all values in one column

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问题 I want to create a Query that will give the total of all values in a single column of my SQLite datase. I want this query to be within a method that returns the total as an int so that I can then further process it within a different activity. How can I do so? I have already created similar methods within my Database helper class (see below), but I do not know how to implement a query within SQLite to give the total. Declaration and creation of database in Databasehelper: (the column i want

CoreData database not showing in sqlite since moving to Xcode 5

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问题 I have an app that uses a CoreData database the contents of which I view using sqlite . The database path is the same: /Users/Comp1/Library/Application Support/iPhone Simulator/7.0.3/Applications/16226A0A-575C-4356-BFAA-6B1A009C0585/Documents and I can see the database file. But when I open it in sqlite there appears to be no data, although I can read through the app. It was working fine until I loaded Xcode 5. Does anyone know why this might be? No tables shown: 回答1: What happens when you

Select query returns “value: not positioned on a valid record” in Qt

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问题 I have been working on a small code which is supposed to fill up columns on a QTableWidget with values fetched from a SQL table. Here's a small snippet: QString path = "C:\\ENTRIES.db"; QString itemToSearch = "ABC"; //This comes as a parameter to a slot actually, assigning it here for simplicity QSqlDatabase db = QSqlDatabase::addDatabase("QSQLITE"); db.setDatabaseName(path); db.open(); QSqlQuery query(db); query.prepare("SELECT * FROM METADATA WHERE ITEM LIKE ':item %'"); query.bindValue("

Android sqlite rowcount is always zero?

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问题 I've used the GUI to create a DB which has 1650 records in it. I'm trying to query this DB but it's always returning nothing. I've tried writing a simple getrowcount() method to see if I'm getting anything at all, but it always returns zero. I must be missing something obvious here, if someone can help point out what's going on. In my main app.java : db = new DbHandler(this); String sIcao1 = "ROW COUNT = " + String.valueOf(db.getRowCount()); In my dbhandler.java : package com.jammo.mywidget4;