I am using sqlite database in Flutter. with provide and sqlite libraries. I want to get ordered list of String in the database when I get the list from sqlite. How can I achieve this? Thank you for your response!
You can use orderBy variable inside query method like this:
Future<List<SingleShiftModel>> getShiftModelsForParticularGroup(
String groupId) async {
Database db = await database;
final List<Map<String, dynamic>> maps = await db.query(
allShiftsTableName,
where: 'parentId = ?',
orderBy: "date ASC", // here you can add your custom order exactly like sqlite but EXCLUDE `ORDER BY`.
whereArgs: [groupId],
);
return List.generate(
maps.length,
(i) => SingleShiftModel.toShiftModelObject(maps[i]),
);
}
Related
I have the following SQL query, which works:
await sequelize.query(
"DELETE FROM `table_name` WHERE (?) IN (?)",
{
replacements: ["project_id", projectIds],
type: QueryTypes.DELETE,
}
);
But I also want to use a replacement for table_name like this:
await sequelize.query(
"DELETE FROM (?) WHERE (?) IN (?)",
{
replacements: ["table_name", "project_id", projectIds],
type: QueryTypes.DELETE,
}
);
But this doesn't work and generates an error about SQL syntax. How can I make this work?
You are mixing data value binding and quoting identifiers.
There is ancient issue in the repo: https://github.com/sequelize/sequelize/issues/4494, which sounds like the problem above.
I believe you can create a workaround that respects different sql dialects like this:
const queryInterface = sequelize.getQueryInterface();
const tableName = queryInterface.quoteIdentifier("projects");
const columnName = queryInterface.quoteIdentifier("project_id");
await sequelize.query(`DELETE FROM ${tableName} WHERE ${columnName} IN (?)`, {
replacements: [project_ids],
type: QueryTypes.DELETE,
});
Assuming you are using sequelize 6.x.
I am using Node and Express with MSNODESQLV8 to write an API demo (my first) to get some rows from a remote SQL Server instance. My other get queries work fine when searching for an ID which is a number but I am unsure how to pass a value in the form of characters to a parameter in my query. Pretty sure req.params.id is not appropriate.
app.get("/productsname/:id", (req, res) => {
const productName = req.params.id;
const productsNameQuery = "SELECT * FROM Products WHERE ProductName = ?";
sql.query(connStr, productsNameQuery, [productName], (err, rows) => {
if (err) {
console.log(`Failed to get product by id ${req.params.id}. ${err}`);
res.sendStatus(500);
}else {
res.json(rows);
}
})
});
I want to take a product name (string?) in at the end of the url where it reads "id" and pass it as a value to the productName const. The end goal is to retrieve all rows from the SQL table where the product name is "processor" in the get url (http://localhost:2000/productname/proccesor). Perhaps I am passing the url incorrectly?
Apologies if this is really basic. I am very new to this.
Thanks in advance
Still trying to get familiar with scalikejdbc. What is the simplest way to just use sql syntax to send a query using scalike jdbc into a table to get max date? Something really simple like the below works fine but gives me an error when I try to add max around the column.
val maxDate: Option[String] = DB readOnly { implicit session =>
sql"select <column> from <table>"
.map(rs => rs.string("<column")).first.apply()
}
this does not work:
val maxDate: Option[String] = DB readOnly { implicit session =>
sql"select max(<column>) from <table>"
.map(rs => rs.string("<column")).first.apply()
}
error:
Failed to retrieve value because The column name not found.. If you're using SQLInterpolation,...
I expect this happens because column max(MyColumn) does not have name "MyColumn" by default. You may try something like this instead
val maxDate: Option[String] = DB readOnly { implicit session =>
sql"select max(MyColumn) as MyColumn_max from MyTable"
.map(rs => rs.string("MyColumn_max")).first.apply()
}
I want to retrieve a single item of data from my database to then use as a value for an input element.
Using the below will retrieve each instance of SubmittedBy in the DB so results in multiple results.
var UserId = WebSecurity.CurrentUserId;
var db = Database.Open("testDB");
var selectQueryString = "Select SubmittedBy FROM Posts WHERE UserId=#0";
var data = db.Query(selectQueryString, UserId);
#foreach(var row in data)
{
<input type="email" name="emailfrom" id="emailfrom" value="#SubmittedBy"/>
}
How do I retrieve SubmittedBy so it only gives the one result i.e. without the foreach loop?
Thanks in advance!!!
If by your data restriccions are you going to obtain 1 and only 1 value for an specific UserId, you could use
var SubmyttedValue = db.QueryValue(selectQueryString, UserId);
There is a method created specifically for this purpose called QuerySingle - just change your query like this:
var data = db.QuerySingle(selectQueryString, UserId);
I hope this helps!
Change your query like this:
Select SubmittedBy FROM Posts WHERE UserId=#0 LIMIT 1
I have an query like:
SELECT id as OfferId FROM offers
WHERE concat(partycode, connectioncode) = ?
AND CURDATE() BETWEEN offer_start_date
AND offer_end_date AND id IN ("121211, 123341,151512,5145626 ");
Now I want to cache the results of this query using memcache and so my question is
How can I cache an query using memcache.
I am currently using CURDATE() which cannot be used if we want to implement caching and so how can I get current date functionality without using CURDATE() function ?
Something like this should work:
function getOffers($ids) {
$key = implode(',', $ids);
$cache = new Memcache();
$cache->connect('localhost');
$content = $cache->get($key);
if ($content === false) {
// content is not cached, so we have to run the query
$content = $yourDb->query('your query here');
$cache->add($key, $content);
}
$cache->close();
return $content;
}
getOffers(array('121211','123341','151512','5145626'));
You can take this a step further by sorting $ids so that the same "set" of IDs (but in a different order) will still take advantage of an available cache for that set.
This isn't date-sensitive, but you can make it date sensitive by adding the date string to $key