I'm trying to do a bitwise operation while setting a column using JOOQ and MySQL. The statement I'm trying to convert to JOOQ is:
UPDATE users SET permission = permission | 16;
Is there a way todo this in JOOQ?
Use DSL.bitOr()
ctx.update(USERS)
.set(USERS.PERMISSION, bitOr(USERS.PERMISSION, 16))
.execute();
Related
I know there is no support for updateOnDuplicate for postgresQL by Sequelize sequelize doc, so is there a work around for this?
Can it be implemented via "SQL command".
New sequelize (v5) includes updateOnDuplicate feature for all dialects
Fields to update if row key already exists (on duplicate key update)?
(only supported by MySQL, MariaDB, SQLite >= 3.24.0 & Postgres >=
9.5). By default, all fields are updated.
Check here : Docs
You can use as
model.bulkCreate(dataToUpdate, { updateOnDuplicate: ["user_id", "token", "created_at"] })
There is some work around. See upsert function. When used in Postgresql it creates custom function in database. Unfortunately there is no bulkUpsert, so you either use it in some for-loop or execute raw SQL as suggested here.
Is there any way to generate SQLite database model from Java code using JOOQ?
You can generate DDL statements like CREATE TABLE .. or ALTER TABLE .. ADD CONSTRAINT .. using the DSLContext.ddl() API, for instance:
// SCHEMA is the generated schema that contains a reference to all generated tables
Queries ddl =
DSL.using(configuration)
.ddl(SCHEMA);
for (Query query : ddl.queries()) {
System.out.println(query);
}
This is documented here:
https://www.jooq.org/doc/latest/manual/sql-building/ddl-statements/generating-ddl/
USE users_tracking;
SELECT user_name FROM visits
where port_name IN
(SELECT port_name FROM ports where location = 'NY' )//as temp;
It gives an error
mismatched input 'SELECT' expecting RULE_T_R_PAREN
Is there any way I can store the inner query in a variable and then use that?
I tried using set#varname := query but it does not recognize the set command.
Nested queries are not allowed in Cassandra CQL. For this kind of complex querying feature you'll need to use Hive or SparkSQL.
Here is a full CQL reference,
http://cassandra.apache.org/doc/cql3/CQL.html
Is there a Model or Instance method that will perform an insert or update, depending on the whether or not the record exists? Preferably making use of MySQL's "INSERT ON DUPLICATE KEY UPDATE" syntax?
they have recently added this feature upsert or insertOrUpdate
/**
* Insert or update a single row. An update will be executed if a row
* which matches the supplied values on either the primary key or a unique
* key is found. Note that the unique index must be defined in your sequelize
* model and not just in the table. Otherwise you may experience a unique
* constraint violation, because sequelize fails to identify the row that
* should be updated.
*/
Model.upsert({uniqueKey: 1234, name: 'joe'}).then(function () {
// cheer for joy
});
Sequelize does not currently support upsert - I believe it was hard to introduce a good cross dialect solution.
You can however do a findOrCreate and a updateAttributes.
Edit: Sequelize does now support UPSERT with a pretty decent cross dialect implementation, see: https://github.com/sequelize/sequelize/pull/2518
Now you can use upsert in Sequelize
Is there an easy way to check if table (column family) is defined in Cassandra using CQL (or API perhaps, using com.datastax.driver)?
Right now I am leaning towards executing SELECT 1 FROM table and checking for exception but maybe there is a better way?
As of 1.1 you should be able to query the system keyspace, schema_columnfamilies column family. If you know which keyspace you want to check, this CQL should list all column families in a keyspace:
SELECT columnfamily_name
FROM schema_columnfamilies WHERE keyspace_name='myKeyspaceName';
The report describing this functionality is here: https://issues.apache.org/jira/browse/CASSANDRA-2477
Although, they do note that some of the system column names have changed between 1.1 and 1.2. So you might have to mess around with it a little to get your desired results.
Edit 20160523 - Cassandra 3.x Update:
Note that for Cassandra 3.0 and up, you'll need to make a few adjustments to the above query:
SELECT table_name
FROM system_schema.tables WHERE keyspace_name='myKeyspaceName';
The Java driver (since you mentioned it in your question) also maintains a local representation of the schema.
Driver 3.x and below:
KeyspaceMetadata ks = cluster.getMetadata().getKeyspace("myKeyspace");
TableMetadata table = ks.getTable("myTable");
boolean tableExists = (table != null);
Driver 4.x and above:
Metadata metadata = session.getMetadata();
boolean tableExists =
metadata.getKeyspace("myKeyspace")
.flatMap(ks -> ks.getTable("myTable"))
.isPresent();
I just needed to manually check for the existence of a table using cqlsh.
Possibly useful general info.
describe keyspace_name.table_name
If it doesn't exist you'll get 'table_name' not found in keyspace 'keyspace'
If it does exist you'll get a description of the table.
For the .NET driver CassandraCSharpDriver version 3.17.1 the following code creates a table if it doesn't exist yet:
var ks = _cassandraSession.Cluster.Metadata.GetKeyspace(keyspaceName);
var tableNames = ks.GetTablesNames();
if(!tableNames.Contains(tableName.ToLowerInvariant()))
{
var stmt = new SimpleStatement($"CREATE TABLE {tableName} (id text PRIMARY KEY, name text, price decimal, volume int, time timestamp)");
_cassandraSession.Execute(stmt);
}
You will need to adapt the list of table columns to your needs. This can also be awaited by using await _cassandraSession.ExecuteAsync(stmt).ConfigureAwait(false) in an async method.
Also, I want to mention that I'm using Cassandra version 4.0.1.