I have a database table with transactions. In one of the fields there is an XML message, the field type is “xml”. In this XML there is an employee filed and it is this field that I need to search. I want to retrieve all the rows that match the employee number supplied at runtime. Is it possible to do this with Linq ?
Shown here is some example XML from one of the rows in the transaction table. The field is called “Message”. I need to look at the “employee” value and return the row if it match what was supplied by the user.
<interface>
<mac>1452345234</mac>
<device>device1</device>
<id>1234567</id>
<terminal>
<unit>1</unit>
<trans>
<event>A3</event>
<employee>3333</employee>
<time>2008-10-02T11:41:00.0000000+00:00</time>
</trans>
</terminal>
</interface>
Yes, it is easily possible with LINQ:
var matchList = from t in transactions
where XDocument.Load (new StringReader (t.Message))
.Descendants ("employee")
.Count (node => node.Value == employeeNr) > 0
select t;
Simple way:
List<YourRecord> GetRecords(string EmployeeId)
{
return TheTable.where(r => r.Message.Contains("<employee>" + empId + "</employee>")).ToList();
}
Related
I have a table with a text column and I would like to select all rows that match the list of search parameters that were provided by the user:
select * from value where value.text in ('Mary', 'Steve', 'Walter');
In addition, I want to notify the user if any of his search terms could not be found. Let's say 'Steve' does not exist in the value.text column, how can I write a query that will show 'Steve'? As that information does not exist in any table, I have no idea how it could be done using a SQL query.
The actual Hibernate code looks like this:
List<String> searchItemList = new ArrayList<>();
searchItemList.add("Mary");
searchItemList.add("Steve");
searchItemList.add("Walter");
Query query = em.createQuery("select v from Value as v where v.text in ( :searchitemlist )");
query.setParameter("searchitemlist", searchItemList);
List result = query.getResultList();
log.info("{}", result.size());
log.info("{}", result);
The searchItemList is a list of all search terms provided by the user. Can be a few hundreds lines long. The current workaround is to search the value table once for each searchItem and note all queries that return 0 rows. That is rather inefficient, surely there is a better approach? Please advise.
You can use the following query to get an array of search items that exist in the database
SELECT DISTINCT value.text from value where value.text in ('Mary', 'Steve', 'Walter');
after running this query, If we assume that the answer is stored in an array called result, notExistSearchListItems will give you the final result
IEnumerable<string> notExistSearchListItems = searchItemList.Except(result);
Currently, I have a GORM query that calculates a counter for each table entry using a second table and returns the first table with a new field "locks_total" which doesn't exist in the original.
Now, what I want to achieve is the same table returned (with the new "locks_total" field) but filtered with "locks_total" = 0.
I can't seem to make it happen because it doesn't recognize this field in the table, what can I do to make it happen? is it possible to run the query and then execute the filter on the new result table?
This is how we currently do it-
txn := dao.postgresManager.DB().Model(&models.SecretMetadataResponse{})
txn.Table(dao.firstTableName + " as s").
Select("s.*, (SELECT COUNT(*) FROM " + dao.secondTableName + " as l where s.id = l.secret_id) locks_total ")
var secretsTotal int64
var metadataResponseEntries []models.SecretMetadataResponse
txn = txn.Count(&secretsTotal). // Saving the count before trimming according to the pagination parameters
Limit(params.Limit).
Offset(params.Offset).
Order(constants.FieldName).
Order(constants.FieldId).
Find(&metadataResponseEntries)
When the SecretMetadataResponse contains the SecretMetadata which is the same fields as in the table and the LocksTotal is the new calculated field that we want to have.
type SecretMetadataResponse struct {
SecretMetadata
LocksTotal int `json:"locks_total"`
}
Thanks in advance :)
I have a database with a json field which has multiple parts including one called tags, there are other entries as below but I want to return only the fields with "{"tags":{"+good":true}}".
"{"tags":{"+good":true}}"
"{"has_temps":false,"tags":{"+good":true}}"
"{"tags":{"+good":true}}"
"{"has_temps":false,"too_long":true,"too_long_as_of":"2016-02-12T12:28:28.238+00:00","tags":{"+good":true}}"
I can get part of the way there with this statement in my where clause trips.metadata->'tags'->>'+good' = 'true' but that returns all instances where tags are good and true including all entries above. I want to return entries with the specific statement "{"tags":{"+good":true}}" only. So taking out the two entries that begin has_temps.
Any thoughts on how to do this?
With jsonb column the solution is obvious:
with trips(metadata) as (
values
('{"tags":{"+good":true}}'::jsonb),
('{"has_temps":false,"tags":{"+good":true}}'),
('{"tags":{"+good":true}}'),
('{"has_temps":false,"too_long":true,"too_long_as_of":"2016-02-12T12:28:28.238+00:00","tags":{"+good":true}}')
)
select *
from trips
where metadata = '{"tags":{"+good":true}}';
metadata
-------------------------
{"tags":{"+good":true}}
{"tags":{"+good":true}}
(2 rows)
If the column's type is json then you should cast it to jsonb:
...
where metadata::jsonb = '{"tags":{"+good":true}}';
If I get you right, you can check text value of the "tags" key, like here:
select true
where '{"has_temps":false,"too_long":true,"too_long_as_of":"2016-02-12T12:28:28.238+00:00","tags":{"+good":true}}'::json->>'tags'
= '{"+good":true}'
I have a table with multiple column and I want to return a column name using another column name as search criteria. How do I achieve this in yii2?
Below is sample code, normal sql should be:
$name = SELECT type_name FROM ProductTable WHERE type_id = 1;
echo $name;
This should return the value of the column type_name where the value of the column type_id equals 1. I tried this, but it doesn't work
$type_name = ProductTable::find()->where(['type_id' =>$model->type_id]);
$type_name = Product::find(['type_name'])->where(['type_id' =>$model->type_id]);
I also tried this, but I guess it was wrong
I hope my question is clear enough and any help will he appreciated
and u could also use createCommand!
$name = \Yii::$app->getDb()->createCommand("SELECT type_name FROM ProductTable WHERE type_id=:typeId", ['typeId'=>$model->type_id])->queryAll();
For a general introduction to Yii2's ActiveRecord, see the guide: http://www.yiiframework.com/doc-2.0/guide-db-active-record.html
If you want the complete row and have a model, you're just missing a one():
Product::find()->where(['type_id' =>$model->type_id])->one();
If you do have a Model defined and just want a single value, try:
Product::find()->select('type_name')->where(['type_id' =>$model->type_id])->scalar();
Which basically generates an ActiveQuery via the model, and changes it to return only the first column in the first row of matched results.
If you do NOT have a model, you could also generate a normal query without ActiveRecord usage (http://www.yiiframework.com/doc-2.0/yii-db-query.html)
$name = (new Query())->select('type_name')
->from('ProductTable')
->where(['type_id' =>$model->type_id])
->scalar();
I assume you generated ProductTable by using Gii module.
Also, if type_id column is a primary key:
$product = ProductTable::findOne($model->type_id);
if($product !== null) { $product->typeName /*... read value ...*/}
or to get all records
$products = ProductTable::findAll($model->type_id); //match all records.
for any other column use the following syntax instead:
$product = ProductTable::findOne(['type_id' => $model->type_id]);
Use following code to get type_name
$PTable=ProductTable::find()->select('type_name')->where(['type_id' =>$model->type_id])->one();
echo $PTable->type_name;
I'm attemping to do a simple check for an empty collection in an NHIbernate Query. Here's my code:
var query = QueryNotDeleted().Where(x=>x.Markets.Count() > 0);
QueryNotDeleted returns an IQueryOver. The above line throws an error (Unrecognised method call in epression x.Markets.Count()) because it doesn't recognize the Count() in the query.
I tried
var query = QueryNotDeleted().Where(x=>x.Markets != null);
But unfortunately, Markets is never NULL, so I have to test for a count instead of it being null to get the records I want.
How can I get this "count" syntax correct so that it excludes records where the Markets property is empty?
I was able to get it to work using:
query.RootCriteria.CreateAlias("Markets", "m", JoinType.LeftOuterJoin);
and then
query.RootCriteria.Add(Restrictions.IsNotNull("m.Id"));
If I understand your question correctly you want to get a list of records that don't have corresponding children?
If I wanted to get a list of Orders that have no OrderItems using QueryOver then I would do something like:-
var orders = session.QueryOver<Order>()
.Left.JoinQueryOver(w => w.Items)
.Where(w => w.Order.Id == null);
If this is not the right answer then please can you submit the SQL you are trying to run and the parent/children mappings/.