Package net.sf.basedb.core.dbengine

Class TableInfo

java.lang.Object
net.sf.basedb.core.dbengine.TableInfo
public class TableInfo extends Object
Holds minimal but useful information about a table in the database. The information can be populated either from Hibernate mappings or from JDBC metadata about the database. This makes it possible to compare the structure of the current database with the information in the Hibernate mapping documents.

The main reason for this class to exists is that we want to solve the problem Hibernate has with creating indexes when doing an update. The information in this class makes it possible to find which indexes are missing. As a bonus we also have code to drop and re-create all indexes.

Version:
2.0
Author:
nicklas
Last modified
$Date: 2021-06-07 11:22:59 +0200 (Mon, 07 Jun 2021) $

  • Field Details

  • Constructor Details

    • TableInfo

      private TableInfo(Table table)

    • TableInfo

      @Deprecated public TableInfo(Table table, DatabaseMetaData metaData) throws SQLException
      Deprecated.
      In 3.14, use TableInfo(Table, DatabaseMetaData, String, String) instead
      Create table info by reading JDBC metadata from the current database
      Parameters:
      table - The Hibernate table object
      metaData - The JDBC metadata connected to the current database
      Throws:
      SQLException - If there is an error

    • TableInfo

      public TableInfo(Table table, DatabaseMetaData metaData, String defaultCatalog, String defaultSchema) throws SQLException
      Create table info by reading JDBC metadata from the current database
      Parameters:
      table - The Hibernate table object
      metaData - The JDBC metadata connected to the current database
      defaultCatalog - Catalog to use if the table doesn't specify a catalog
      defaultSchema - Schema to use if the table doesn't specify a catalog
      Throws:
      SQLException - If there is an error
      Since:
      3.4

    • TableInfo

      public TableInfo(Table table, Dialect dialect)
      Create table info by reading the Hibernate mappings.
      Parameters:
      table - The Hibernate table object
      dialect - The current database dialect

  • Method Details

    • listTables

      public static List<Table> listTables(DatabaseMetaData metaData, String catalog, String schema) throws SQLException
      List all tables that are present in the given catalog and/or schema.
      Parameters:
      metaData - A metadata object that is connected to a database
      catalog - The name of the catalog, or null
      schema - The name of the schema, or null
      Returns:
      A list of tables
      Throws:
      SQLException
      Since:
      3.1

    • getTable

      public Table getTable()
      Get the table this information is representing.
      Returns:
      The table object
      Since:
      3.1

    • existsInDb

      public boolean existsInDb()
      Check if the table exists in the database or not. This value is only meaningful if the TableInfo object was created from JDBC metadata using TableInfo(Table, DatabaseMetaData).
      Since:
      3.1

    • makeSafe

      private String makeSafe(String name)
      Sometime the database put quotes around names. This method strips all extra characters.
      Parameters:
      name - The name to make safe, or null
      Returns:
      The safe name or null
      Since:
      2.1.1

    • getColumns

      public Set<TableInfo.ColumnInfo> getColumns()
      Get information about the columns in the table.
      Returns:
      A set containing information about each column

    • getPrimaryKey

      public TableInfo.PrimaryKeyInfo getPrimaryKey()
      Get information about the primary key of the table
      Returns:
      A PrimaryKeyInfo object, or null if the table doesn't have a primary key

    • getForeignKeys

      public Set<TableInfo.ForeignKeyInfo> getForeignKeys()
      Get information about the foreign keys in the table.
      Returns:
      A set containing information about each foreign key

    • findForeignKeyName

      public String findForeignKeyName(String name, Set<String> columns, String refName)
      Check if there is a foreign key with the same name or exactly the same set of columns referencing the same table.
      Parameters:
      name - The name of the foreign key to look for, or null to only use the columns
      columns - A set containing the column names that should be present in the foreign key
      refName - The referenced table
      Returns:
      The name of the foreign key, or null if no foreign key was found
      Since:
      3.8

    • getIndexes

      public Set<TableInfo.IndexInfo> getIndexes()
      Get information about the indexes in the table. Note! Some databases ie. MySQL, uses indexes to keep track of foreign and primary keys. This means that the information in this set includes one index for each primary/foreign key in addition to those indexes created for other reasons.
      Returns:
      A set containing information about each index

    • safeToDrop

      public boolean safeToDrop(TableInfo.IndexInfo ii)
      It is safe to drop an index if it is not the primary key.
      Parameters:
      ii - The IndexInfo object we want to check if it is safe to drop
      Returns:
      TRUE if is safe to drop the index, FALSE otherwise

    • findIndexName

      public String findIndexName(String name, Set<String> columns)
      Check if there is an index with the same name or exactly the same set of columns.

      Hibernate doesn't generate a name for multi-column indexes or unique constraints, which means that we have to find any index matching the column names. In case, Hibernate starts generating the indexes with names, we check against the name as well.

      Parameters:
      name - The name of the index to look for, or null to only use the columns
      columns - A set containing the column names that should be present in the index
      Returns:
      The name of the index, or null if no index was found

    • findAll

      public List<TableInfo.IndexInfo> findAll(Set<String> columns)
      Find all indexes with the given set of columns. Used for getting rid of duplicates.
      Parameters:
      columns - A set containing the column names that should be present in the index
      Returns:
      A list with the index information or an empty list of no index is found
      Since:
      3.4

    • findColumn

      public TableInfo.ColumnInfo findColumn(String column)
      Find information about a column with the given name.
      Parameters:
      column - The name of the column
      Returns:
      The column information or null if no column is found
      Since:
      3.1

    • getFullQuotedTableName

      public String getFullQuotedTableName(DbEngine engine)
      Get the fully quialified and quoted table name using the quoting rules from the given DBEngine
      Parameters:
      engine - A DbEngine
      Returns:
      The fully quoted table name
      Since:
      3.1

    • getRowCount

      public long getRowCount(DbEngine engine, Connection connection, boolean approximate) throws SQLException
      Count the number of rows in the table.
      Parameters:
      connection - The connection to user for counting
      Throws:
      SQLException
      Since:
      3.1