我想输入一个查询,以便在将数据插入数据库时检查数据库是否重复,这样就可以防止在数据库中多次输入活动名称
function insertQueryDB(tx) {
var myDB = window.openDatabase("test", "1.0", "Test DB", 1000000);
tx.executeSql('CREATE TABLE IF NOT EXISTS dataEntryTb (id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, activityName TEXT NOT NULL, location TEXT NOT NULL, time NOT NULL, date NOT NULL, reporter NOT NULL)');
var an = document.forms["myForm"]["activityName"].value;
var l = document.forms["myForm"]["location"].value;
var t = document.forms["myForm"]["time"].value;
var d = document.forms["myForm"]["date"].value;
var r = document.forms["myForm"]["reporter"].value;
var query = 'INSERT INTO dataEntryTb ( activityName, location, time, date, reporter) VALUES ( "'+an+'", "'+l+'", "'+t+'", "'+d+'", "'+r+'")';
navigator.notification.alert("Retrieved the following: Activity Name="+an+" and Location="+l);
tx.executeSql(query,[]);
}``
答案 0 :(得分:1)
创建名称为unique
的表格:
CREATE TABLE IF NOT EXISTS dataEntryTb (
id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
activityName TEXT NOT NULL UNIQUE,
location TEXT NOT NULL,
time NOT NULL, date NOT NULL,
reporter NOT NULL
);
如果名称已经在表中,数据库将返回错误。