I am trying to add new columns dynamically from Spring Boot application. Let us say, each time an event e occurs, I want to add a column into a Cassandra table with a well defined column-name and type. I have tried this code:
#Query("alter table attributes.attributedata add ?0 ?1")
public void addColumn(String columnName, String dataType);
Error Log:
org.springframework.cassandra.support.exception.CassandraQuerySyntaxException: line 1:41 no viable alternative at input 'gac5' (alter table attributes.attributedata add ['gac]...); nested exception is com.datastax.driver.core.exceptions.SyntaxError: line 1:41 no viable alternative at input 'gac5' (alter table attributes.attributedata add ['gac]...)
at org.springframework.cassandra.support.CassandraExceptionTranslator.translateExceptionIfPossible(CassandraExceptionTranslator.java:132)
at org.springframework.cassandra.core.CqlTemplate.potentiallyConvertRuntimeException(CqlTemplate.java:946)
at org.springframework.cassandra.core.CqlTemplate.translateExceptionIfPossible(CqlTemplate.java:930)
at org.springframework.cassandra.core.CqlTemplate.translateExceptionIfPossible(CqlTemplate.java:912)
at org.springframework.cassandra.core.CqlTemplate.doExecute(CqlTemplate.java:278)
at org.springframework.cassandra.core.CqlTemplate.doExecute(CqlTemplate.java:559)
at org.springframework.cassandra.core.CqlTemplate.doExecute(CqlTemplate.java:549)
at org.springframework.cassandra.core.CqlTemplate.query(CqlTemplate.java:485)
at org.springframework.cassandra.core.CqlTemplate.query(CqlTemplate.java:510)
at org.springframework.cassandra.core.CqlTemplate.query(CqlTemplate.java:505)
at org.springframework.data.cassandra.core.CassandraTemplate.selectOne(CassandraTemplate.java:638)
at org.springframework.data.cassandra.core.CassandraTemplate.selectOne(CassandraTemplate.java:509)
at org.springframework.data.cassandra.repository.query.CassandraQueryExecution$SingleEntityExecution.execute(CassandraQueryExecution.java:104)
at org.springframework.data.cassandra.repository.query.CassandraQueryExecution$ResultProcessingExecution.execute(CassandraQueryExecution.java:143)
at org.springframework.data.cassandra.repository.query.AbstractCassandraQuery.execute(AbstractCassandraQuery.java:113)
at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.doInvoke(RepositoryFactorySupport.java:483)
at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:461)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.data.projection.DefaultMethodInvokingMethodInterceptor.invoke(DefaultMethodInvokingMethodInterceptor.java:56)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.data.repository.core.support.SurroundingTransactionDetectorMethodInterceptor.invoke(SurroundingTransactionDetectorMethodInterceptor.java:57)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:213)
I have also tried to store the entire query into a string and then directly place the string into value such that
#Query(value="?0")
but that does not work either.
This code works perfectly fine. If the values obtained from the function are not enclosed within single inverted commas, the code would work.
#Query("alter table attributes.attributedata add dummy text")
public void addColumn(String columnName, String dataType);
Is there any way this could work? Please suggest the possible alternatives.
A cluster object can be created as shown in the code, followed by the session object on which the query is executed. The name and type of the column to be added are passed as parameters.
public void addColumn(String columnName, String columnType){
//Query
String query = "ALTER TABLE keyspace.tablename ADD " + columnName + " " + columnType;
//Creating Cluster object
Cluster cluster = Cluster.builder().addContactPoint("127.0.0.1").build();
//Creating Session object
Session session = cluster.connect();
//Executing the query
session.execute(query);
System.out.println("Column added");
}
In order to optimize the code, we can create the session object only once during the application startup. The implementation for such scenario is given below:
private Session session;
#EventListener(ApplicationReadyEvent.class)
private void createSessionObject(){
//Creating Cluster object
Cluster cluster = Cluster.builder().addContactPoint("127.0.0.1").build();
//Creating Session object
Session session = cluster.connect();
}
public void addColumn(String columnName, String columnType){
//Query
String query = "ALTER TABLE keyspace.tablename ADD " + columnName + " " + columnType;
if(session == null){
createSessionObject();
}
//Executing the query
session.execute(query);
System.out.println("Column added");
}
You can try something like this using CONCAT
#Query("alter table attributes.attributedata add CONCAT('%',:columnNameDataType,'%')")
public void addColumn(String columnNameDataType);
Check this link
Related
When i want to modify the database via JPQL i have to mark the query as Transactional and Modiyfing. If i do so, the return type of the method representing the query has to be either void or int(representing the number of edited rows i think). Why are only the two return types allowed? If i do a HTTP-PUT request and update the object with an own JPQL query, i would like to return the updated object again. Whats the best way to do it if the return type of the query has to be void or int? Do i have to do a seperate query/request again which selects the object after it was updated?
EDIT:
Thats how i call the query:
if (inactivityListDTO.getProjectIds().size() > 0) {
projectRepository.updateProjectsIsArchivedByProjectIds(inactivityListDTO.getProjectIds(), inactivityListDTO.getIsArchived());
}
Thats the query:
#Transactional
#Modifying
#Query("UPDATE Project project SET project.isArchived = :isArchived,
project.archivedDate = current_date " +
"WHERE project.id IN :ids")
void updateProjectsIsArchivedByProjectIds(#Param("ids") List<Long> ids, #Param("isArchived") boolean isArchived);
Because it finally boils down to execute a standard UPDATE SQL in the DB , and the UPDATE in standard SQL only returns the number of records being updated and does not return a result set.
And yes , if you need get a record 's value after update , you have to query it again. Alternatively , you should consider using a JPA way to update a record , which first query the object , then update it by changing its state . Something like below (Assume you are using spring #Transactional to manage the transactional boundary):
#Transactional
public void changeEmployeeSalary(Integer employeeId , Integer salary){
Employee employee = entityManager.find(Employee.class , employeeId);
employee.setSalary(salary);
}
In this way , you do not need to query the record again after it is updated and you also do not need to manually write a UPDATE SQL.
I want to get subquery from impala table as one dataset.
Code like this:
String subQuery = "(select to_timestamp(unix_timestamp(now())) as ts from my_table) t"
Dataset<Row> ds = spark.read().jdbc(myImpalaUrl, subQuery, prop);
But result is error:
Caused by: java.sql.SQLDataException: [Cloudera][JDBC](10140) Error converting value to Timestamp.
I can use unix_timestamp function,but to_timestmap failed, why?
I found code in org.apache.spark.sql.execution.datasources.jdbc.JDBC.compute() exists some problem:
sqlText = s"SELECT $columnList FROM ${options.table} $myWhereClause"
$columList contains " like "col_name" , when I delete " it work fine.
I solve this problem by add dialect, default dialect will add "" to column name,
JdbcDialect ImpalaDialect = new JdbcDialect(){
#Override
public boolean canHandle(String url) {
return url.startsWith("jdbc:impala") || url.contains("impala");
}
#Override
public String quoteIdentifier(String colName) {
return colName;
}
};
JdbcDialects.registerDialect(ImpalaDialect);
I am fairly new to spring ,I am looking to check if a certain email id exists in database or not , using Spring Jdbc Template ,I looked here but could'nt find the proper answer .I am looking something like ,SELECT count(*) from table where email=?
Any help will be appreciated.
You can do something as below if you are using jdbctemplate and new version of spring
private boolean isEmailIdExists(String email) {
String sql = "SELECT count(*) FROM table WHERE email = ?";
int count = jdbcTemplate.queryForObject(sql, new Object[] { email }, Integer.class);
return count > 0;
}
queryForObject method of jdbcTemplate accepts the sql query as the first parameter, second argument is an array of objects for the sql query place holders and the third argument is the expected return value from the sql query.
In this case we only have one place holder and hence I gave the second argument as new Object[] { email } and the result we are expecting is a count which is a Integer and hence I gave it as Integer.class
I kind of got this answer from https://www.mkyong.com/spring/jdbctemplate-queryforint-is-deprecated/
You can go through it if you are interested.
private boolean isEmailIdExists(String email) {
return jdbcTemplate.queryForObject("SELECT EXISTS(SELECT FROM table WHERE email = ?)", Boolean.class, email);
}
http://www.postgresqltutorial.com/postgresql-exists/
I am executing multiple queries concurrently and retrieving the results. But, the queries belong to multiple tables so, when resultset is retrieved, it is difficult to identify that a resultset belong to which table.
Can anyone help here as to how to identify the table names for each query resultset?
I tried below code but table name is blank!!!!
public static void getColumnNames(ResultSet rs) throws SQLException {
if (rs == null) {
return;
}
// get result set meta data
ResultSetMetaData rsMetaData = rs.getMetaData();
int numberOfColumns = rsMetaData.getColumnCount();
// get the column names; column indexes start from 1
for (int i = 1; i < numberOfColumns + 1; i++) {
String columnName = rsMetaData.getColumnName(i);
// Get the name of the column's table name
String tableName = rsMetaData.getTableName(i);
System.out.println("column name=" + columnName + " table=" + tableName + "");
}
}
I am calling this method like this:
jdbcTemplate.query(sql, new ResultSetExtractor<ResultSet>() {
#Override
public ResultSet extractData(ResultSet resultSet) throws SQLException,
DataAccessException {
getColumnNames(resultSet);
return resultSet;
}
});
Please advise, what is done wrong here? :(
You're not doing anything wrong here. The problem is caused by the method itself in connection with your DBMS or your JDBC driver, respectively.
See this doc please. 'table name or "" if not applicable' suggests that in your case the DBMS/driver does not provide the required information, causing the method to return an empty string.
I'm afraid, you'll have to find another way to detect which query the result originated from.
I am trying to access database FK using named SQL query with Hibernate, the idea is to query a customer table which contains name, and companyId,etc. CompanyId is the FK for a commpany table. The query I wrote is as follows:
#NamedNativeQuery(name="getcustomer", query="Select CUSTOMER.* from CUSTOMER,COMPANY where CUSTOMER_FIRST_NAME = (?1) and CUSTOMER_LAST_NAME= (?2) and CUSTOMER_COMPANY_ID_FK = (?3) ",resultClass=Customer.class)
The issue I am currently having as follow:
Exception in thread "main" org.hibernate.QueryParameterException:
Position beyond number of declared ordinal parameters. Remember that
ordinal parameters are 1-based! Position: 2 at
org.hibernate.engine.query.spi.ParameterMetadata.getOrdinalParameterDescriptor(ParameterMetadata.java:89)
at
org.hibernate.engine.query.spi.ParameterMetadata.getOrdinalParameterExpectedType(ParameterMetadata.java:109)
at
org.hibernate.internal.AbstractQueryImpl.determineType(AbstractQueryImpl.java:507)
at
org.hibernate.internal.AbstractQueryImpl.setParameter(AbstractQueryImpl.java:479)
at
com.comresource.scrapmetalapp.DAOImpl.CustomerDAOImpl.searchCustomer(CustomerDAOImpl.java:61)
at
com.comresource.scrapmetalapp.ServiceImpl.CustomerServiceImpl.searchCustomer(CustomerServiceImpl.java:39)
at com.comresource.scrapmetalapp.Config.Run.main(Run.java:57)
My DAO implementation is like this:
#Override
public Customer searchCustomer(String fName, String lName, Integer company) {
Session session = sessionFactory.openSession();
return (Customer) session.getNamedQuery("getcustomer").setParameter(1, fName)
.setParameter(2, lName)
.setParameter(3, company)
.uniqueResult();
}
What is the issue here?
For this, I would need to see how you are associating the mapping in your model class, but the query should go like this.
public Customer getMeThatCustomer(String param1, String param2, int foreignkey){
session = getCurrentSession();
org.hibernate.Query query = session.createQuery("From Customer as c where c.name=:param1 and c.lastname=:param2 and c.company.companyid=:foreignkey");
//Note the last parameter, where I have mentioned c.company, in place of
company, there should be the foregin key association and then the primary key in java class.
query.setParameter("param1",param1);
query.setP...er("param2",param2);
quer.....("companyid",companyid);
return (Customer) query.uniqueResult();
}
So, try it out, let me know if there is any problem