Package org.javalite.activejdbc

Class Base

java.lang.Object
org.javalite.activejdbc.Base
public class Base extends Object
This class provides a number of convenience methods for opening/closing database connections, running various types of queries, and executing SQL statements. This class differs from DB such that in this class you a logical name for a connection is hard-coded to be "default". Use this class when you have only one database.

This class is a convenience wrapper of DB
Author:
Igor Polevoy, Eric Nielsen

  • Method Details

    • open

      public static DB open()
      This method will open a connection defined in the file 'database.properties' set by an initial previous call to DBConfiguration.loadConfiguration(String). The connection picked up from the file is defined by ACTIVE_ENV environment variable or active_env system property. If this variable is not defined, it defaults to 'development' environment. If there is JUnit on classpath, this method assumes it is running under test, and defaults to 'test'.

    • open

      public static DB open​(String driver, String url, String user, String password)
      Opens a new connection based on JDBC properties and attaches it to a current thread.
      Parameters:
      driver - class name of driver
      url - URL connection to DB
      user - user name.
      password - password.

    • open

      public static DB open​(String driver, String url, Properties props)
      Opens a new connection in case additional driver-specific parameters need to be passed in.
      Parameters:
      driver - driver class name
      url - JDBC URL
      props - connection properties

    • open

      public static DB open​(String jndiName)
      Opens a connection from JNDI based on a registered name. This assumes that there is a jndi.properties file with proper JNDI configuration in it.
      Parameters:
      jndiName - name of a configured data source.

    • open

      public static DB open​(String jndiName, Properties jndiProperties)
      Opens a new connection from JNDI data source by name using explicit JNDI properties. This method can be used in cases when file jndi.properties cannot be easily modified.
      Parameters:
      jndiName - name of JNDI data source.
      jndiProperties - JNDI properties

    • open

      public static DB open​(DataSource dataSource)
      Opens a connection from a datasource. This methods gives a high level control while sourcing a DB connection.
      Parameters:
      dataSource - datasource will be used to acquire a connection.

    • connection

      public static Connection connection()
      Returns connection attached to a current thread and named "default".
      Returns:
      connection attached to a current thread and named "default".

    • hasConnection

      public static boolean hasConnection()
      Use to check if there is a default connection present on current thread.
      Returns:
      true if finds default connection on current thread, false if not.

    • close

      public static void close​(boolean suppressWarning)
      Closes connection and detaches it from current thread.
      Parameters:
      suppressWarning - true to not display a warning in case of a problem (connection not there)

    • close

      public static void close()
      Closes connection and detaches it from current thread.

    • count

      public static Long count​(String table)
      Returns count of rows in table.
      Parameters:
      table - name of table.
      Returns:
      count of rows in table.

    • count

      public static Long count​(String table, String query, Object... params)
      Runs a count query, returns a number of matching records.
      Parameters:
      table - table in which to count rows.
      query - this is a filtering query for the count. If '*' provided, all records will be counted. Example: "age > 65 AND department = 'accounting'"
      params - parameters for placeholder substitution.
      Returns:
      copunt number of records found in a table.

    • firstCell

      public static Object firstCell​(String query, Object... params)
      Returns a value of the first column of the first row. This query expects only one column selected in the select statement. If more than one column returned, it will throw IllegalArgumentException.
      Parameters:
      query - query
      params - parameters
      Returns:
      fetched value, or null if query did not fetch anything.

    • findAll

      public static List<Map<String,​Object>> findAll​(String query, Object... params)
      This method returns entire resultset as one list. Do not use it for large result sets. Example: 
       List<Map> people = Base.findAll("select * from people where first_name = ?", "John");
 for (Map person : people)
     System.out.println(person.get("first_name"));
      Parameters:
      query - raw SQL query. This query is parametrized.
      params - list of parameters for a parametrized query.
      Returns:
      entire result set corresponding to the query.

    • firstColumn

      public static List firstColumn​(String query, Object... params)
      This method returns entire resultset as one list. Do not use it for large result sets. Example: 
        List ssns = Base.firstColumn("select ssn from people where first_name = ?", "John");
  for(Object ssn: ssns)
      System.out.println(ssn);
      This methods expects a query which selects only one column from a table/view. It will throw an exception if more than one columns are fetched in a result set.
      Parameters:
      query - raw SQL query. This query is parametrized.
      params - list of parameters for a parametrized query.
      Returns:
      entire result set corresponding to the query.

    • findAll

      public static List<Map<String,​Object>> findAll​(String query)
      This method returns entire resultset as one list. Do not use it for large result sets.
      Parameters:
      query - raw SQL query. This query is not parametrized.
      Returns:
      entire result set corresponding to the query.

    • find

      public static RowProcessor find​(String query, Object... params)
      Executes a raw query and returns an instance of RowProcessor. Use it in the following pattern: 
       Base.find("select first_name, last_name from really_large_table").with(new RowListenerAdapter() {
            public void onNext(Map row) {
                ///write your code here
                Object o1 = row.get("first_name");
                Object o2 = row.get("last_name");
            }
        });
      The JDBC fetch size defaults to 10 records. This means that the driver will fetch and accumulate 10 records in memory. Once you read them, the driver will fetch the next 10, and so on. If you want a finer control over a fetch size, use the find(RowProcessor.ResultSetType, RowProcessor.ResultSetConcur, int, String, Object...) method
      Parameters:
      query - raw SQL.
      params - list of parameters if query is parametrized.
      Returns:
      instance of RowProcessor which has with() method for convenience.

    • find

      public static RowProcessor find​(RowProcessor.ResultSetType type, RowProcessor.ResultSetConcur concur, int fetchSize, String query, Object... params)
      Executes a raw query and returns an instance of RowProcessor. Use it in the following pattern: 
         Base.find("select first_name, last_name from really_large_table", ....).with(new RowListenerAdapter() {
     public void onNext(Map row) {
     ///write your code here
     Object o1 = row.get("first_name");
     Object o2 = row.get("last_name");
     }
     });
      See ResultSet Docs
      Parameters:
      query - raw SQL.
      type - type of result set
      concur - concurrent mode of result set
      fetchSize - hint to the JDBC driver for the size of result set. Gives the JDBC driver a hint as to the number of rows that should be fetched from the database when more rows are needed for ResultSet objects generated by this Statement. If the value specified is zero, then the hint is ignored and an entire set maybe loaded into your heap space - be careful out there!
      params - list of parameters if query is parametrized.
      Returns:
      instance of RowProcessor which has with() method for convenience.

    • find

      public static void find​(String sql, RowListener listener)
      Executes a raw query and calls instance of RowListener with every row found. Use this method for very large result sets.
      Parameters:
      sql - raw SQL query.
      listener - client listener implementation for processing individual rows.

    • exec

      public static int exec​(String query)
      Executes DML. Use it for inserts and updates.
      Parameters:
      query - raw DML.
      Returns:
      number of rows afected by query.

    • exec

      public static int exec​(String query, Object... params)
      Executes parametrized DML - will contain question marks as placeholders.
      Parameters:
      query - query to execute - will contain question marks as placeholders.
      params - query parameters.
      Returns:
      number of records affected.

    • openTransaction

      public static void openTransaction()
      Opens local transaction.

    • commitTransaction

      public static void commitTransaction()
      Commits local transaction.

    • rollbackTransaction

      public static void rollbackTransaction()
      Rolls back local transaction.

    • startBatch

      public static PreparedStatement startBatch​(String parametrizedStatement)
      Creates a java.sql.PreparedStatement to be used in batch executions later.
      Parameters:
      parametrizedStatement - Example of a statement: INSERT INTO employees VALUES (?, ?).
      Returns:
      instance of java.sql.PreparedStatement with compiled query.

    • addBatch

      public static void addBatch​(PreparedStatement ps, Object... parameters)
      Adds a batch statement using given java.sql.PreparedStatement and parameters.
      Parameters:
      ps - java.sql.PreparedStatement to add batch to.
      parameters - parameters for the query in java.sql.PreparedStatement. Parameters will be set on the statement in the same order as provided here.

    • executeBatch

      public static int[] executeBatch​(PreparedStatement ps)
      Executes a batch on java.sql.PreparedStatement.
      Parameters:
      ps - java.sql.PreparedStatement to execute batch on.
      Returns:
      an array of update counts containing one element for each command in the batch. The elements of the array are ordered according to the order in which commands were added to the batch.
      See Also:
      Statement#executeBatch()

    • closePreparedStatement

      public static void closePreparedStatement​(PreparedStatement ps)
      Quietly closes the java.sql.PreparedStatement used in a batch execution. The advantage over calling java.sql.PreparedStatement.close() directly is not having to explicitly handle a checked exception (java.sql.SQLException). This method should typically be called in a finally block. So as not to displace any exception (e.g. from a failed batch execution) that might already be in flight, this method swallows any exception that might arise from closing the statement. This is generally seen as a worthwhile trade-off, as it much less likely for a close to fail without a prior failure.
      Parameters:
      ps - java.sql.PreparedStatement with which a batch has been executed. If null, this is a no-op.

    • attach

      public static void attach​(Connection connection)
      Attaches a database connection to current thread under a default name.
      Parameters:
      connection - instance of connection to attach to current thread.

    • detach

      public static Connection detach()
      Detaches a default connection from current thread and returns an instance of it. This method does not close a connection. Use it for cases of advanced connection management, such as integration with Spring Framework.
      Returns:
      instance of a default connection detached from current thread by name passed to constructor.

    • withDb

      public static <T> T withDb​(String jndiName, Properties jndiProperties, Supplier<T> supplier)
      Same as DB.withDb(String, Properties, Supplier), but with db name DB.DEFAULT_NAME.

    • withDb

      public static <T> T withDb​(DataSource dataSource, Supplier<T> supplier)
      Same as DB.withDb(DataSource, Supplier), but with db name DB.DEFAULT_NAME.

    • withDb

      public static <T> T withDb​(String jndiName, Supplier<T> supplier)
      Same as DB.withDb(String, Supplier), but with db name DB.DEFAULT_NAME.

    • withDb

      public static <T> T withDb​(String driver, String url, Properties properties, Supplier<T> supplier)
      Same as DB.withDb(String, Properties, Supplier), but with db name DB.DEFAULT_NAME.

    • withDb

      public static <T> T withDb​(String driver, String url, String user, String password, Supplier<T> supplier)
      Same as DB.withDb(String, String, String, String, Supplier), but with db name DB.DEFAULT_NAME.

    • withDb

      public static <T> T withDb​(Supplier<T> supplier)
      Same as DB.withDb(Supplier), but with db name DB.DEFAULT_NAME.