I want to read from DB and create a CSV file. In order to do that I am using camel-jdbc and camel-bindy.
First I set the body with the SELECT statement.
SELECT [vendor],
[ean],
[itemid] AS itemId,
[quantity]
FROM [dbo].[ElectronicDeliveryNotes]
then I call the jdbc component
<to uri="jdbc:dataSource?outputType=SelectList&outputClass=com.xxx.Model"/>
This will return a List of Model. Model class is
#CsvRecord(separator = ";", generateHeaderColumns = true, crlf = "UNIX")
public class Model2 {
#DataField(pos = 1, columnName = "A_Liererant")
private String vendor;
#DataField(pos = 2, columnName = "F_EAN")
private String ean;
#DataField(pos = 3, columnName = "G_Lief. Artikelnummer")
private String itemId;
#DataField(pos = 4, columnName = "H_Menge")
private BigDecimal quantity;
//getters setters
I am getting the following error:
java.lang.IllegalArgumentException: Cannot map all properties to bean of type class com.xxx.Model2. There are 1 unmapped properties. {itemid=11.0441-5402.2}
From my understanding the problem is in the naming of model properties. One solution that I tried and worked is to rename the Model itemId => itemid. This will work, but i am not using Java naming conventions.
Do you know how to overcome this without renaming properties?
I also tried the following but it didn't work.
#DataField(pos = 3, columnName = "G_Lief. Artikelnummer", name = "itemid")
private String itemId;
I didn't see anything wrong with your code structure.
If what you want to accomplish is retrieving from a table and export its results to a CSV based on your Model2 class, I may suggest using camel-sql. Could be something like:
#Override
protected RoutesBuilder createRouteBuilder() throws Exception {
return new RouteBuilder() {
#Override
public void configure() throws Exception {
getContext().getComponent("sql", SqlComponent.class).setDataSource(db);
BindyCsvDataFormat camelDataFormat = new BindyCsvDataFormat(Model2.class);
from("sql:select vendor, ean, itemid as itemId, quantity from ElectronicDeliveryNotes?outputType=SelectList&outputClass=com....model.Model2")
.marshal(camelDataFormat)
.log("the body:\n${body}")
.to("mock:result");
}
};
}
You poll the data from the table, marshall it and then send the message to other queue. I've run some tests to make sure that the query results could be transformed into a CSV and as long as you keep the fields' name equals to your property, nothing seems to go wrong. (side note: in my tests even without the alias everything went fine).
But, testing your code, I went in the same error. Maybe you need to implement the beanRowMapper:
To use a custom org.apache.camel.component.jdbc.BeanRowMapper when using outputClass. The default implementation will lower case the row names and skip underscores, and dashes. For example "CUST_ID" is mapped as "custId".
My guess this is the reason why you are stuck in this error:
java.lang.IllegalArgumentException: Cannot map all properties to bean of type class com.xxx.Model2. There are 1 unmapped properties. {itemid=11.0441-5402.2}
Try renaming your alias to ITEM_ID.
Related
I want to save both child and parent entities whenever a POST call is made. I have an Item entity with a one to one mapping to a parent table Attribute:
#Entity
#Table(name="Item")
#JsonIgnoreProperties(ignoreUnknown = true)
public class Item
{
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name="id")
private Long id;
#OneToOne(fetch=FetchType.LAZY)
#JoinColumn(name="attr_id")
private Attribute attribute;
#OneToMany(mappedBy = "item", cascade = CascadeType.ALL, orphanRemoval=true)
private List<ValueSet> valueSets = new ArrayList<>();
// Other fields, getters, setters, overriding equals and hashcode using Objects.equals() and Objects.hashCode() for all the fields, helper for adding and removing ValueSet
}
The Attribute entity looks like this:
#Entity
#Table(name="Attribute")
#JsonIgnoreProperties(ignoreUnknown = true)
public class Attribute
{
#Id
#Column(name="id")
private Long id;
// Other fields, getters, setters, NOT overriding equals hashCode
}
Whenever an Item gets saved I need the Attribute to get saved as well. I've my postman sending JSON POST data as follows:
{
"attribute":{
"id":"6"
},
"valueSets":[
{
"value":"basic"
}
]
}
My handler looks like this:
#PostMapping("/item")
public void postItems(#RequestBody Item item)
{
itemRepository.save(item);
}
ItemRepository is just a one liner with #Repository annotation:
public interface ItemRepository extends CrudRepository<Item, Long>
When I try to save the Item I run into - Cannot insert the value NULL into column 'attr_id', table 'Item'; column does not allow nulls. INSERT fails.
I can't figure out why is it unable to take the id value of 6 that I am supplying as part of my POST invocation. The id value 6 already exists on the Attribute table. I have also tried making the relationship bi-directional using mappedBy and CASCADE.ALL but still get the same error.
Any thoughts/suggestions on what I'm messing/missing? Also, is there a better approach to handle nested entities? Should I try to save each of them individually? In that case can the #RequestBody still be the parent entity?
I have built an example project, and try to replicate your situation, not successful. I am able to insert the "item" without any issue.
I placed the project under this repository https://github.com/hepoiko/user-5483731-1
Hope this help you to troubleshooting further or let me know If I miss anything in there.
I'm seeing a very bizarre issue with iBatis when trying to read a property from a Java map using isEqual, but not with other iBatis operators. For example it is able to read the map properties fine when using isNotNull and iterate. The xml:
<isNotNull property="filterCriteria.account">
AND
id
<isEqual property="filterCriteria.account.meetsCriteria" compareValue="false">
NOT
</isEqual>
IN
(SELECT DISTINCT id
FROM account
WHERE some other criteria....
)
</isNotNull>
The 2 java classes we're using here:
public class SearchProfile {
private Map<String, SearchProfileCriteria> filterCriteria;
public SAOSearchProfile() {
filterCriteria = new HashMap<>();
}
public Map<String, SAOSearchProfileCriteria> getFilterCriteria() {
return filterCriteria;
}
public void setFilterCriteria(Map<String, SAOSearchProfileCriteriaBase> filterCriteria) {
this.filterCriteria = filterCriteria;
}
}
Above is the container object that is passed to iBatis for the querying, and below is the criteria object that will be the value of the map. In this example it is keyed with the String "account"
public class SearchProfileCriteria {
boolean meetsCriteria;
public String getCriteriaAsString() {
return StringUtils.getStringValueFromBoolean(meetsCriteria);
}
public boolean isMeetsCriteria() {
return meetsCriteria;
}
public void setMeetsCriteria(boolean meetsCriteria) {
this.meetsCriteria = meetsCriteria;
}
public String getSQLString(){
return meetsCriteria ? "" : "NOT";
}
}
And the exception:
Cause: com.ibatis.common.beans.ProbeException: There is no READABLE property named 'account' in class 'java.util.Map'; nested exception is com.ibatis.common.jdbc.exception.NestedSQLException:
The getSQLString() method was my half baked attempt at a work around, the String gets escaped in the query and throws a syntax error.
When I remove the <isEqual> block the query executes find, which indicates it is able to read the "account" key when checking the to see if it is null. As I mentioned above, we're also able to use the map keys in <iterate> tags without issue. It seems <isEqual> and <isNotEqual> are the only tags causing issues. Does anyone have experience with this or know what may be going on?
Beware: Using isNotNull, isEqual, iterate is iBatis, they don't exist anymore in Mybatis, so referencing to Mybatis indifferently is confusing.
Reference documentation.
For your issue, how does it behave if replacing Map with a class (property will be known at compile time)?
Or try using <isPropertyAvailable>.
The work around could work with right syntax: $ instead of #: $filterCriteria.account.SQLString$ instead of #filterCriteria.account.SQLString#, then the value is just concatenated instead of bound as parameter.
I tried to play with Dapper Extension & MS Access and succeeded up to certain extent. My code is listed below. All the functions works properly (Insert/Count/GetList/Delete) except Get & Update. I have summarised the code below. If anybody wants I can paste all the code here
My Product class
public class Products
{
public string ProductNumber { get; set; }
public string Description { get; set; }
}
And in my main class. I tried to get the product and update it as below. con.Get<Products> function returns an exception with "Sequence contains more than one element" message and con.Update<Products> returns an exception with "At least one Key column must be defined".
using (var con = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=test.mdb"))
{
string ProductNumber = "12";
var product4 = con.Get<Products>(ProductNumber);
product4.ProductNumber = "Baz";
con.Update<Products>(product4);
Console.ReadLine();
}
Even though con.Get<Products> fails con.GetList<Products>(predicate) works perfectly. I did follow this link for setup
If DapperExtensions can't infer a key property called ID from your class, you'll need to explicitly specify one via a class mapper. Assuming the ProductNumber is the primary key in the database, the following example class mapper should set the ProductNumber to be the primary key for DapperExtensions.
using Dapper;
using DapperExtensions;
using DapperExtensions.Mapper;
public class ProductsMapper : ClassMapper<Products>
{
public ProductsMapper()
{
Map(x => x.ProductNumber).Key(KeyType.Assigned);
AutoMap();
}
}
This class can sit somewhere within the same assembly as the rest of your code. Dapper Extensions will automatically pick it up. If you have your classes and Dapper code in separate assemblies, you can point it to your mapper with the following line:
DapperExtensions.DapperExtensions.SetMappingAssemblies({ typeof(ProductsMapper).Assembly })
I am beginning to use Dapper and love it so far. However as i venture further into complexity, i have ran into a big issue with it. The fact that you can pass an entire custom object as a parameter is great. However, when i add another custom object a a property, it no longer works as it tries to map the object as a SQL parameter. Is there any way to have it ignore custom objects that are properties of the main object being passed thru? Example below
public class CarMaker
{
public string Name { get; set; }
public Car Mycar { get; set; }
}
propery Name maps fine but property MyCar fails because it is a custom object. I will have to restructure my entire project if Dapper can't handle this which...well blows haha
Dapper extensions has a way to create custom maps, which allows you to ignore properties:
public class MyModelMapper : ClassMapper<MyModel>
{
public MyModelMapper()
{
//use a custom schema
Schema("not_dbo_schema");
//have a custom primary key
Map(x => x.ThePrimaryKey).Key(KeyType.Assigned);
//Use a different name property from database column
Map(x=> x.Foo).Column("Bar");
//Ignore this property entirely
Map(x=> x.SecretDataMan).Ignore();
//optional, map all other columns
AutoMap();
}
}
Here is a link
There is a much simpler solution to this problem.
If the property MyCar is not in the database, and it is probably not, then simple remove the {get;set;} and the "property" becomes a field and is automatically ignored by DapperExtensions. If you are actually storing this information in a database and it is a multi-valued property that is not serialized into a JSON or similar format, I think you are probably asking for complexity that you don't want. There is no sql equivalent of the object "Car", and the properties in your model must map to something that sql recognizes.
UPDATE:
If "Car" is part of a table in your database, then you can read it into the CarMaker object using Dapper's QueryMultiple.
I use it in this fashion:
dynamic reader = dbConnection.QueryMultiple("Request_s", param: new { id = id }, commandType: CommandType.StoredProcedure);
if (reader != null)
{
result = reader.Read<Models.Request>()[0] as Models.Request;
result.reviews = reader.Read<Models.Review>() as IEnumerable<Models.Review>;
}
The Request Class has a field as such:
public IEnumerable<Models.Review> reviews;
The stored procedure looks like this:
ALTER PROCEDURE [dbo].[Request_s]
(
#id int = null
)
AS
BEGIN
SELECT *
FROM [biospecimen].requests as bn
where bn.id=coalesce(#id, bn.id)
order by bn.id desc;
if #id is not null
begin
SELECT
*
FROM [biospecimen].reviews as bn
where bn.request_id = #id;
end
END
In the first read, Dapper ignores the field reviews, and in the second read, Dapper loads the information into the field. If a null set is returned, Dapper will load the field with a null set just like it will load the parent class with null contents.
The second select statement then reads the collection needed to complete the object, and Dapper stores the output as shown.
I have been implementing this in my Repository classes in situations where a target parent class has several child classes that are being displayed at the same time.
This prevents multiple trips to the database.
You can also use this approach when the target class is a child class and you need information about the parent class it is related to.
I can't find any documentation or examples I can follow to use the SqlBuilder class.
I need to generate sql queries dynamically and I found this class. Would this be the best option?
the best place to start is to checkout the dapper source code from its github repo and have a look at the SqlBuilder code. The SqlBuilder class is only a 200 lines or so and you should be able to make an informed choice on whether it is right for your needed.
An other option is to build your own. I personally went down this route as it made sense. Dapper maps select querys directly to a class if you name your class properties the same as your database or add an attribute such as displayName to map from you can use reflection to get the property names. Put there names and values into a dictionary and you can genarate sql fairly easy from there.
here is something to get you started:
first an example class that you can pass to your sqlbuilder.
public class Foo
{
public Foo()
{
TableName = "Foo";
}
public string TableName { get; set; }
[DisplayName("name")]
public string Name { get; set; }
[SearchField("fooId")]
public int Id { get; set; }
}
This is fairly basic. Idea behind the DisplayName attribute is you can separate the properties out that you want to include in your auto generation. in this case TableName does not have a DisplayName attribute so will not be picked up by the next class. however you can manually use it when generating your sql to get your table name.
public Dictionary<string, object> GetPropertyDictionary()
{
var propDictionary = new Dictionary<string, object>();
var passedType = this.GetType();
foreach (var propertyInfo in passedType.GetProperties())
{
var isDef = Attribute.IsDefined(propertyInfo, typeof(DisplayNameAttribute));
if (isDef)
{
var value = propertyInfo.GetValue(this, null);
if (value != null)
{
var displayNameAttribute =
(DisplayNameAttribute)
Attribute.GetCustomAttribute(propertyInfo, typeof(DisplayNameAttribute));
var displayName = displayNameAttribute.DisplayName;
propDictionary.Add(displayName, value);
}
}
}
return propDictionary;
}
This method looks at the properties for its class and if they are not null and have a displayname attribute will add them to a dictionary with the displayname value as the string component.
This method is designed to work as part of the model class and would need to be modified to work from a separate helper class. Personally I have it and all my other sql generation methods in a Base class that all my models inherit from.
once you have the values in the dictionary you can use this to dynamically generate sql based on the model you pass in. and you can also use it to populate your dapper DynamicParamaters for use with paramiterized sql.
I hope this helps put you on the right path to solving your problems.