What I have is a code like this one below
var innerQuery = knex('foo_table').select('bar_column')
var joinTable = knex('some_table').select('bar_column')
knex(innerQuery).innerJoin(joinTable,joinTable.bar_column,innerQuery.bar_column)
it gives me
routine: "errorMissingColumn"
I have tried giving tables allias but it was same mistake.
Knex does allow variables in .innerJoin, but the variable must be a function. It gets passed the query builder object (or, in the case of non-arrow functions, you can use this. as the query builder). So you could do something like this:
const innerQuery = knex('foo_table').select('bar_column')
const onBarColumn = qb => qb.on('foo_table.bar_column', '=', 'some_table.bar_column')
const joinTable = qb => qb('some_table').innerJoin('foo_table', onBarColumn)
innerQuery.innerJoin(joinTable)
You can build it up gradually like this if it works better for you. Obviously, the above helpers could be wrapped to make the arguments more flexible.
Related
I'm looking for a way to capture the raw SQL for all the queries that the Objection.js library executes with the bindings interpolated into the SQL string.
I realize that there's a Knex event handler that I can take advantage of but the second argument to the on('query', data) is an object containing an SQL template with the bindings separate.
e.g.
{
sql: "select \"accounts\".* from \"accounts\" where \"id\" = ?",
bindings: [1]
}
I'm wondering if the most elegant way to do this would be to use something like the .toString() method that exists on the QueryBuilder but I don't think a specific instance of a QueryBuilder is available in the callback. Ideally I don't reinvent the wheel and re-write Knex's interpolation method.
Any pointers would be greatly appreciated.
Thank you!
You can use the .toKnexQuery() function to pull out the underlying knex query builder and gain access to .toSQL() and .toQuery().
I tested and verified the following example using version 2 of Objection. I couldn't find .toKnexQuery() in the version 1 docs and therefore can't verify it will work with earlier versions of Objection.
// Users.js
const { Model } = require('objection')
class Users extends Model {
static get tableName() { return 'users' }
// Insert jsonSchema, relationMappings, etc. here
}
module.exports = Users
const Users = require('./path/to/Users')
const builder = Users.query()
.findById(1)
.toKnexQuery()
console.log(builder.toQuery())
// "select `users`.* from `users` where `users`.`id` = 1"
console.log(builder.toSQL())
// {
// method: 'select',
// bindings: [ 1 ],
// sql: 'select `users`.* from `users` where `users`.`id` = ?'
// }
It should probably be reiterated that in addition to .toString(), .toQuery() can also be vulnerable to SQL injection attacks (see here).
A more "responsible" way to modify the query might be something like this (with MySQL):
const { sql, bindings } = Users.query()
.insert({ id: 1 })
.toKnexQuery()
.toSQL()
.toNative()
Users.knex().raw(`${sql} ON DUPLICATE KEY UPDATE foo = ?`, [...bindings, 'bar'])
Knex / objection.js does not provide any methods that can securely do the interpolation. .toString() can produce invalid results in some cases and they can be vulnerable to sql injection attacks.
If it is only for debugging purposes looking how .toQuery() is implemented helps. https://github.com/knex/knex/blob/e37aeaa31c8ef9c1b07d2e4d3ec6607e557d800d/lib/interface.js#L12
knex.client._formatQuery(sql, bindings, tz)
It is not a public API though so it is not guaranteed to be the same even between patch versions of knex.
I am trying to perform an update using strongly-typed objects. For example,
public void setAppointmentPrefs(string UserName, IEnumerable<AppointmentInfo> info)
{
var query = new QueryDocument {{ "ProviderId", UserName}};
var update = Update.Set("Prefs",prefs); // prefs.toList() gives same error
// providerprefs initialized in constructor
providerprefs.Update(query, update);
}
I receive a compiler error saying:Error 14 The best overloaded method match for 'MongoDB.Driver.Builders.Update.Set(string, MongoDB.Bson.BsonValue)' has some invalid arguments
Obviously the Mongo driver will not let me update based on my own object (whether as IEnumerable or prefs.toList()), which seems a contrast from the way it permits me to insert or query with custom objects. Surely I am missing something obvious that would permit me to avoid deserializing, weakly typing then creating a generic BsonDocument!! TIA.
You can do an Update based on your own types! Have you tried using the typed Query and Update builders?
Try something like this:
var query = Query<AppointmentInfo>.EQ(i => i.ProviderId, userName);
var update = Update<AppointmentInfo>.Set(i => i.Prefs, info.Prefs);
Not sure I got the types and everything write from your partial code, but that should give you the general idea.
Let me know if you have any further questions.
I know this has been answered but I for one don't fully understand Roberts answer.
All I did is call the "ToBsonDocument()" method for it to except the object as a parameter
So:
customObject.ToBsonDocument()
If you have an array of objects inside a document:
var query = Query.EQ("_id", ObjectId.Parse(id.ToString()));
var update = Update.Push("ArrayOfObjects", customObject.ToBsonDocument());
collection.Update(query, update);
I use Entity Framework 4.1 Code First. I want to call a stored procedure that has an output parameter and retrieve the value of that output parameter in addition to the strongly typed result set. Its a search function with a signature like this
public IEnumerable<MyType> Search(int maxRows, out int totalRows, string searchTerm) { ... }
I found lots of hints to "Function Imports" but that is not compatible with Code First.
I can call stored procedures using Database.SqlQuery(...) but that does not work with output parameters.
Can I solve that problem using EF4.1 Code First at all?
SqlQuery works with output parameters but you must correctly define SQL query and setup SqlParameters. Try something like:
var outParam = new SqlParameter();
outParam.ParameterName = "TotalRows";
outParam.SqlDbType = SqlDbType.Int;
outParam.ParameterDirection = ParameterDirection.Output;
var data = dbContext.Database.SqlQuery<MyType>("sp_search #SearchTerm, #MaxRows, #TotalRows OUT",
new SqlParameter("SearchTerm", searchTerm),
new SqlParameter("MaxRows", maxRows),
outParam);
var result = data.ToList();
totalRows = (int)outParam.Value;
I have a situation where I'm trying to filter a LINQ select using a derived sub class.
ctx.BaseEntity.OfType<SubClass>() - this works fine.
However I'd like to do this using a string value instead. I've come across a performance barrier when I have lots (>20) Sub Classes and selecting an Entity without using OfType just isn't an option. I have a generic UI that renders from the base class, so I don't know what Class Type will be returned at compile time.
So what I'd like to do is this:
Perform a projected Select where I
return just the SubClassType from
the database
Perform a second select
using this value as the OfType to
only select the relevant related
entity from the database (No mass
unions generated)
int id = 1;
var classType = (from c in ctx.BaseClass.Include("ClassType")
where c.id == id
select new
{
c.ClassType.TypeName
}).First();
BaseClass caseQuery = ctx.BaseClass.OfType<classType.TypeName>()
.Include("ClassType")
.Include("ChildEntity1")
.Include("ChildEntity2")
.Where(x => x.id== id);
But obviously this won't work because OfType requires a Type and not a string.
Any ideas on how I can achieve this?
Update:
As a side note to the original question, it turns out that the moment you project a query that uses a Navigation Property - it builds the monster SQL too, so I've ended up using a stored procedure to populate my ClassType entity from the BaseClass Id.
So I've just got it to work using eSQL, which I'd never used before. I've posted the code here just in case it helps someone. Has anyone else got a more strongly typed solution they can think of?
BaseClass caseQuery = ctx.BaseClass.CreateQuery<BaseClass>("SELECT VALUE c FROM OFTYPE(Entities.[BaseClass],namespace.[" + classType.TypeName + "]) as c")
.Include("ClassType")
.Include("ChildEntity1")
.Include("ChildEntity2")
.Where(x => x.id== id).FirstOrDefault();
To answer the headline question about calling OfType with a string / runtime type, you can do the following:
// Get the type, assuming the derived type is defined in the same assembly
// as the base class and you have the type name as a string
var typeToFilter = typeof(BaseClass)
.Assembly
.GetType("Namespace." + derivedTypeName);
// The use reflection to get the OfType method and call it directly
MethodInfo ofType = typeof(Queryable).GetMethod("OfType");
MethodInfo ofTypeGeneric = method.MakeGenericMethod(new Type[] { typeToFilter });
var result = (IQueryable<Equipment>)generic.Invoke(null, new object[] { equipment });
Combine this with your stored procedure to get the class name and you (should?) avoid the massive join - I don't have table-per-type implementation to play with so I can't test.
I'm trying to use a select object to filter the results of a many to many rowset. This call works great:
$articles = $this->model->findArticlesViaArticlesUsers();
This however does not:
$articles = new Default_Model_Articles();
$articleSelect = $articles->select();
$articleSelect->where("status = 'published'")
->order("date_published DESC")
->limit(1);
$articles = $this->model->findArticlesViaArticlesUsers($articleSelect);
That throws the following error:
exception 'Zend_Db_Select_Exception'
with message 'You cannot define a
correlation name 'i' more than once'
I can't figure out how to successfully get "articles that have the status of 'published'" using the magic many-to-many relationship (nor findManyToManyRowset). I'm at the end of my rope and thinking of just writing the sql manually. Any ideas?
When defining the select statement, you must use the same object that you call findManyToManyRowset (or whatever magic function you use) on.
Ex:
$articles = new Default_Model_Articles();
$user = $articles->find($userId)->current();
$select = $user->select();
$select->where('status = ?', 'published');
$articles = $user->findArticlesViaArticlesUsers($select);
Notice the select statement and findArticlesViaArticlesUsers are both extending $user. Thats the key.
I think you've misunderstood how the relationships work.
See this manual page - you should call the magic method, findArticlesViaArticlesUsers, on a Row object. In this case, I think you want to find a User, and then call findArticles... on that.