Qt创建SQlite数据库的示例代码
Qt 创建 sqlite数据库
void Widget::initDB()
{
// 创建并打开数据库
QSqlDatabase database;
database = QSqlDatabase::aDDDatabase("QSQLITE");
// qDebug() << QApplication::applicationDirPath(); // 获取应用程序当前目录
database.setDatabaseName("test.sqlite3");
if(!database.open())
{
qDebug() << "Error: Failed to connect database." << database.lastError();
}
else
{
qDebug() << "Succeed to connect database.";
}
// 创建表格
QSqlQuery sql_query = database.exec("DROP TABLE student");
// 先清空一下表,可按需添加此句
// sql_query.exec("DROP TABLE student");
// 创建表格student
if(!sql_query.exec("create table student(UserId int primary key, UserName text, PassWord text)"))
{
qDebug() << "Error: Fail to create table." << sql_query.lastError();
}
else
{
qDebug() << "Table created!";
}
// 填充表
if(!sql_query.exec("INSERT INTO student VALUES(1, 'AppleCai', '23')"))
{
qDebug() << "Error: Fail to create table." << sql_query.lastError();
}
else
{
qDebug() << "add one created!";
}
// 批量填充表
QStringList names;
names << "小A" << "小B" << "小C" << "小D" << "小E" << "小F" << "小G" << "小H" << "小I";
QStringList password;
password << "12" << "23" << "34" << "45" << "56" << "67" << "78" << "89" << "90";
// 绑定关键字后才能进行操作
sql_query.prepare("INSERT INTO student (UserId, UserName, PassWord) "
"VALUES (:UserId, :UserName, :PassWord)");
qint8 i = 0;
foreach (QString name, names) // 从names表里获取每个名字
{
sql_query.bindValue(":UserId", i+2); // 向绑定值里加入名字
sql_query.bindValue(":UserName", name); // 成绩
sql_query.bindValue(":PassWord", password[i]); // 班级
if(!sql_query.exec())
{
qDebug() << "Error: Fail." << sql_query.lastError();
}
i++;
}
// 读取sqlite
studentInfo tmp;
QVector<studentInfo> infoVect; // 数据库缓存
sql_query.exec("SELECT * FROM student WHERE UserId >= 5 AND UserId <= 9;");
while (sql_query.next())
{
tmp.UserId = sql_query.value(0).toInt();
tmp.UserName = sql_query.value(1).toString();
tmp.Password = sql_query.value(2).toString();
qDebug() << tmp.UserId << tmp.UserName << tmp.Password;
infoVect.push_back(tmp);
}
qDebug("done");
// 更改表中数据
sql_query.prepare("UPDATE student SET PassWord = 'admin' WHERE UserName = 'AppleCai'");
if(!sql_query.exec())
{
qDebug() << "Error: Fail." << sql_query.lastError();
}
// 删除表中数据
sql_query.prepare("DELETE FROM student WHERE UserName = '小H'");
if(!sql_query.exec())
{
qDebug() << "Error: Fail." << sql_query.lastError();
}
}
以下是个人代码备份
这个代码是在qt写的,包含了数据库的创建和写入,但是我在项目准备直接在dataGrip把数据一键导入创建好数据库之后再用qt里面的sql语句读,所以就不需要这一部分了
#include "sqlitedatabase.h"
SqliteDatabase::SqliteDatabase()
{
qDebug() << "hhh";
// initPickNameDB();
}
void SqliteDatabase::initPickNameDB()
{
// 创建并打开数据库
QSqlDatabase database;
database = QSqlDatabase::addDatabase("QSQLITE");
// qDebug() << QApplication::applicationDirPath();
database.setDatabaseName(QApplication::applicationDirPath() + "/CONFIG/" + "PickNameDB.sqlite3");
if(!database.open())
{
qDebug() << "Error: Failed to connect database." << database.lastError();
}
else
{
qDebug() << "Succeed to connect database.";
}
// 创建表格 先清空一下表
QSqlQuery sql_query = database.exec("DROP TABLE department");
sql_query = database.exec("DROP TABLE person");
if(!sql_query.exec("create table department (Id int primary key not null, "
"DeptName vchar(50) not null )"))
{
qDebug() << "Error: Fail to create department table." << sql_query.lastError();
}
else
{
qDebug() << "Department table created!";
}
if(!sql_query.exec("create table person (Id int primary key not null , "
"DeptID integer not null , "
"PerName vchar(50) not null, "
"foreign key(DeptID) references department (Id))"))
{
qDebug() << "Error: Fail to create person table." << sql_query.lastError();
}
// 填充表
// sql_query.exec("insert into department (id, name) values (1, '办领导')");
// sql_query.exec("insert into department (id, name) values (2, '综合处')");
// sql_query.exec("insert into department (id, name) values (3, '政策法规处')");
// sql_query.exec("insert into department (id, name) values (4, '机构改革处')");
// sql_query.exec("insert into department (id, name) values (5, '党群政法行政机构编制管理处')");
// sql_query.exec("insert into department (id, name) values (6, '政府行政机构编制管理处')");
// sql_query.exec("insert into department (id, name) values (7, '市县行政机构编制管理处')");
// sql_query.exec("insert into department (id, name) values (8, '事业机构编制管理处')");
// sql_query.exec("insert into department (id, name) values (9, '事业单位登记管理处')");
// sql_query.exec("insert into department (id, name) values (10, '机构编制监督检查处')");
// sql_query.exec("insert into department (id, name) values (11, '人事处')");
// sql_query.exec("insert into department (id, name) values (12, '机关党委')");
// sql_query.exec("insert into department (id, name) values (13, '省机构编制电子政务中心')");
// sql_query.exec("insert into department (id, name) values (14, '省机构编制研究中心')");
// 批量填充表
QStringList deptNames;
deptNames << "办领导" << "综合处" << "政策法规处" << "机构改革处"
<< "党群政法行政机构编制管理处" << "政府行政机构编制管理处"
<< "市县行政机构编制管理处" << "事业机构编制管理处" << "事业单位登记管理处"
<< "机构编制监督检查处" << "人事处" << "机关党委"
<< "省机构编制电子政务中心" << "省机构编制研究中心";
// 绑定关键字后才能进行操作
sql_query.prepare("INSERT INTO department (Id, DeptName) "
"VALUES (:Id, :DeptName)");
qint8 i = 0;
foreach (QString deptName, deptNames)
{
sql_query.bindValue(":Id", i + 1);
sql_query.bindValue(":DeptName", deptName);
if(!sql_query.exec())
{
qDebug() << "Error: Fail." << sql_query.lastError();
}
i++;
}
// 读取sqlite
department dept;
QVector<department> tmpDept; // 数据库缓存
sql_query.exec("SELECT * FROM ");
}
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