I am trying to build a criteria of comparing the value of a derived property of adding two fields as shown in
Can I do a math operation inside a createCriteria, i.e.
class SumFormula {
Integer column1
Integer column2
Integer sum
static mapping = {
sum formula: 'column1 + column2'
}
}
and the criteria:
SumFormula.createCriteria().list() {
ne("sum", 100)
}
However I could not make it work with MongoDB. The derived property is always null when printed out.
The above cited post did mention that derived properties are SQL expressions, so the questions is that are the derived properties only available with GORM for SQL? Any alternative for GORM for MongoDB?
derived properties are a Hibernate/SQL specific feature and are not supported in GORM for MongoDB. An alternative is to simply do this in code:
class SumFormula {
Integer column1
Integer column2
Integer getSum() { column1 + column2 }
}
We are facing the same problem. Currently, our workaround is to actually store the derived properties in MongoDB and use the beforeUpdate methods to calculate the values.
def beforeUpdate() {
sum = column1 + column2
}
Related
I have a JPA/Hibernate entity which has a JSONB column (using https://github.com/vladmihalcea/hibernate-types ) for storing a list of strings. This works fine so far.
#TypeDef(name = "jsonb", typeClass = JsonBinaryType.class)
#Type(type = "jsonb")
#Column(name = "TAGS", columnDefinition = "jsonb")
private List<String> tags;
Now I want to check if another string is contained in the list of strings.
I can do this by writing a native query and use the #> operator from Postgres. Because of other reasons (the query is more complex) I do not want to go in that direction. My current approach is calling the jsonb_contains method in a Spring Data specification (since the operator is just alias to this function), e.g. jsonb_contains('["tag1", "tag2", "tag3"]','["tag1"]'). What I am struggling with is, getting the second parameter right.
My initial approach is to also use a List of Strings.
public static Specification<MyEntity> hasTag(String tag) {
return (root, query, cb) -> {
if (StringUtils.isEmpty(tag)) {
return criteriaBuilder.conjunction();
}
Expression<Boolean> expression = criteriaBuilder.function("jsonb_contains",
Boolean.class,
root.get("tags"),
criteriaBuilder.literal(List.of(tag)));
return criteriaBuilder.isTrue(expression);
};
}
This results in the following error.
Caused by: org.postgresql.util.PSQLException: ERROR: function jsonb_contains(jsonb, character varying) does not exist
Hinweis: No function matches the given name and argument types. You might need to add explicit type casts.
Position: 375
It does know that root.get("tags") is mapped to JSONB but for the second parameter it does not. How can I get this right? Is this actually possible?
jsonb_contains(jsob, jsonb) parameters must be jsonb type.
You can not pass a Java String as a parameter to the function.
You can not do casting in Postgresql via JPA Criteria.
Using JSONObject or whatever does not help because Postgresql sees it as
bytea type.
There are 2 possible solutions:
Solution 1
Create jsonb with jsonb_build_object(text[]) function and send it to jsonb_contains(jsonb, jsonb) function:
public static Specification<MyEntity> hasTag(String tag) {
// get List of key-value: [key1, value1, key2, value2...]
List<Object> tags = List.of(tag);
// create jsonb from array list
Expression<?> jsonb = criteriaBuilder.function(
"jsonb_build_object",
Object.class,
cb.literal(tags)
);
Expression<Boolean> expression = criteriaBuilder.function(
"jsonb_contains",
Boolean.class,
root.get("tags"),
jsonb
);
return criteriaBuilder.isTrue(expression);
}
Solution 2
Create custom function in your Postgresql and use it in Java:
SQL:
CREATE FUNCTION jsonb_contains_as_text(a jsonb, b text)
RETURNS BOOLEAN AS $$
SELECT CASE
WHEN a #> b::jsonb THEN TRUE
ELSE FALSE
END;$$
LANGUAGE SQL IMMUTABLE STRICT;
Java Code:
public static Specification<MyEntity> hasTag(String tag) {
Expression<Boolean> expression = criteriaBuilder.function(
"jsonb_contains_as_text",
Boolean.class,
root.get("tags"),
criteriaBuilder.literal(tag)
);
return criteriaBuilder.isTrue(expression);
}
I think that the reason is that you pass the varchar as the second param. jsonb_contains() requires two jsonb params.
To check a jsonb array contains all/any values from a string array you need to use another operators: ?& or ?|.
The methods bindings for them in PSQL 9.4 are: jsonb_exists_all and jsonb_exists_any correspondingly.
In your PSQL version, you could check it by the following command:
select * from pg_operator where oprname = '?&'
I'm trying to use jsonb_set to update a range of json objects within my database. I can get a query working that updates the object with a string value, however I cannot seem to get it to update using the current value.
UPDATE entity
SET properties = jsonb_set(properties, '{c_number}', concat('0', properties->>'c_number'))
WHERE type = 1 and length(properties->>'c_number') = 7
The above doesn't work in its current format, I think the issue is the properties->>'c_number' inside the jsonb_set. Is there a way I can access the current value and simply add a leading 0?
Found a solution:
UPDATE entity
SET properties = jsonb_set(properties, '{c_number}', concat('"0', properties->>'c_number', '"')::jsonb)
WHERE type = 1 and length(properties->>'c_number') = 7
Based on this answer I was able to prepare my solution.
My goal was to create a new property in JSON, with a value that is based on the value of one of the properties which my JSON already has.
For example:
I have:
{
property_root: { property_root_child: { source_property_key: "source_property_value" } }
}
I want:
{
property_root: { property_root_child: { source_property_key: "source_property_value", target_property_key: "source_property_value + my custom ending" } }
}
So my query would look:
UPDATE database.table_with_json
SET json_column=jsonb_set(
json_column,
'{ property_root, property_root_child, target_property_key }',
concat('"', json_column->'property_root'->'property_root_child'->>'source_property_key', ' + my custom ending', '"')::jsonb)
WHERE
json_column->'property_root'->'property_root_child'->'source_property_key' IS NOT NULL
Why concat looks messy? Based on the answer mentioned above:
The third argument of jsonb_set() should be of jsonb type. The problem is in casting a text string to jsonb string, you need a string in double quotes.
That is why we have to wrap concat in double qoutes.
I'm learning this wonderful library, however while simple queries work, I'm confused how to write something that not in library FAQ.
For example,
create table if not exists ticks
(id bigserial not null constraint ticks_pkey primary key,
timestamp timestamp not null
);
It it possible to write something like
select coalesce(max(id), 0) from ticks where timestamp::date = ?
Actually, I have 2 issues here
column.max() doesn't have any suitable modifiers, for example, function() accepts no parameters. Probably, I can emulate this in code after I fetch the row.
I have no idea how to make casting in where or write arbitrary where condition.
If it's possible to map object to your existing table then you could try something like:
object Ticks : LongIdTable() {
val timestamp = datetime("timestamp ")
}
fun Expression<DateTime>.pgDate() = object : org.jetbrains.exposed.sql.Function<DateTime>(DateColumnType(false)) {
override fun toQueryBuilder(queryBuilder: QueryBuilder) = queryBuilder {
append(this#pgDate, "::date")
}
}
val expr = Coalesce(Ticks.id.max(), longLiteral(0))
Ticks.slice(expr).select {
Ticks.timestamp.pgDate() eq DateTime.parse("2019-01-01")
}
I have a table on Postgres that auto generates UUIDs, when I dd Customer::all(); on Laravel I get an array with "cs_id" => "d0402be5-e1ba-4cb2-a80c-5340b406e2c3" which is fine. When I loop or select one record with the only the cs_id the data it retuns 0,2,5 for the three records currently on the table which is incorrect data.
EDIT:
CREATE TABLE customers
(
cs_id character varying(255) NOT NULL DEFAULT gen_random_uuid(),
CONSTRAINT cs_customers_pkey PRIMARY KEY (cs_id),
}
On laravel
$customerData = Customer::where('cs_id','d0402be5-e1ba-4cb2-a80c-5340b406e2c3')->first();
dd($customerData['cs_id']);
For some reason Eloquent messes up there.
just add a getter and use it whenever you need the cs_id
public function getGuid()
{
return $this->attributes['cs_id'];
}
To use uuids auto-generated by the database, define your model as follows:
class Customer extends Model
{
// rename the id column (optional)
protected $primaryKey = 'cs_id';
// tell Eloquent that your id is not an integer
protected $keyType = 'string';
// do NOT set $incrementing to false
}
Then you can use all Eloquent's methods as you would with classic ids:
$customerData = Customer::findOrFail('d0402be5-e1ba-4cb2-a80c-5340b406e2c3');
Use Customer::findOrFail('d0402be5-e1ba-4cb2-a80c-5340b406e2c3');
to get the record matching that pk.
I'm assuming on top you have use App\Customer;
There is table customer_account (postgres) which one was migrate from YII2.
DDL:
CREATE TABLE public.test_table (
id INTEGER PRIMARY KEY NOT NULL DEFAULT nextval('test_table_id_seq'::regclass),
data JSONB
);
In go project i try to get value from this table.
type TableGo struct {
Id int
Data string `gorm:"type:jsonb"`
}
table := TableGo{}
db.Where("id = ?", 75).Find(&table)
println(table.Data)
But there is (pq: relation "table_gos" does not exist)
How i can link structure which table without db.AutoMigrate(&TableGo{})?
I think table name in your migration script is wrong. Because it is not in GORM convention. If you want to use that name,you can use following method in your model for custom table name.
func (m *Model) TableName() string {
return "custom_table_name"
}
Found the solution:
func(TableGo) TableName() string {
return "account_status"
}