Class Prepared

java.lang.Object
org.h2.command.Prepared
Direct Known Subclasses:
BackupCommand, Call, DataChangeStatement, DefineCommand, ExecuteImmediate, ExecuteProcedure, Explain, Help, NoOperation, Query, ScriptBase, Set, SetSessionCharacteristics, TransactionCommand
public abstract class Prepared extends Object
A prepared statement.

  • Field Details

    • session

      protected SessionLocal session
      The session.

    • sqlStatement

      protected String sqlStatement
      The SQL string.

    • sqlTokens

      protected ArrayList<Token> sqlTokens
      The SQL tokens.

    • create

      protected boolean create
      Whether to create a new object (for indexes).

    • parameters

      protected ArrayList<Parameter> parameters
      The list of parameters.

    • prepareAlways

      protected boolean prepareAlways
      If the query should be prepared before each execution. This is set for queries with LIKE ?, because the query plan depends on the parameter value.

    • modificationMetaId

      private long modificationMetaId

    • command

      private Command command

    • persistedObjectId

      private int persistedObjectId
      Used to preserve object identities on database startup. 0 if object is not stored, -1 if object is stored and its ID is already read, >0 if object is stored and its id is not yet read.

    • currentRowNumber

      private long currentRowNumber

    • rowScanCount

      private int rowScanCount

    • cteCleanups

      private List<TableView> cteCleanups
      Common table expressions (CTE) in queries require us to create temporary views, which need to be cleaned up once a command is done executing.

  • Constructor Details

    • Prepared

      public Prepared(SessionLocal session)
      Create a new object.
      Parameters:
      session - the session

  • Method Details

    • isTransactional

      public abstract boolean isTransactional()
      Check if this command is transactional. If it is not, then it forces the current transaction to commit.
      Returns:
      true if it is

    • queryMeta

      public abstract ResultInterface queryMeta()
      Get an empty result set containing the meta data.
      Returns:
      the result set

    • getType

      public abstract int getType()
      Get the command type as defined in CommandInterface
      Returns:
      the statement type

    • isReadOnly

      public boolean isReadOnly()
      Check if this command is read only.
      Returns:
      true if it is

    • needRecompile

      public boolean needRecompile()
      Check if the statement needs to be re-compiled.
      Returns:
      true if it must

    • getModificationMetaId

      long getModificationMetaId()
      Get the meta data modification id of the database when this statement was compiled.
      Returns:
      the meta data modification id

    • setModificationMetaId

      void setModificationMetaId(long id)
      Set the meta data modification id of this statement.
      Parameters:
      id - the new id

    • setParameterList

      public void setParameterList(ArrayList<Parameter> parameters)
      Set the parameter list of this statement.
      Parameters:
      parameters - the parameter list

    • getParameters

      public ArrayList<Parameter> getParameters()
      Get the parameter list.
      Returns:
      the parameter list

    • checkParameters

      protected void checkParameters()
      Check if all parameters have been set.
      Throws:
      DbException - if any parameter has not been set

    • setCommand

      public void setCommand(Command command)
      Set the command.
      Parameters:
      command - the new command

    • isQuery

      public boolean isQuery()
      Check if this object is a query.
      Returns:
      true if it is

    • prepare

      public void prepare()
      Prepare this statement.

    • update

      public long update()
      Execute the statement.
      Returns:
      the update count
      Throws:
      DbException - if it is a query

    • query

      public ResultInterface query(long maxrows)
      Execute the query.
      Parameters:
      maxrows - the maximum number of rows to return
      Returns:
      the result set
      Throws:
      DbException - if it is not a query

    • setSQL

      public final void setSQL(String sql, ArrayList<Token> sqlTokens)
      Set the SQL statement.
      Parameters:
      sql - the SQL statement
      sqlTokens - the SQL tokens

    • getSQL

      public final String getSQL()
      Get the SQL statement.
      Returns:
      the SQL statement

    • getSQLTokens

      public final ArrayList<Token> getSQLTokens()
      Get the SQL tokens.
      Returns:
      the SQL tokens

    • getPersistedObjectId

      public int getPersistedObjectId()
      Get the object id to use for the database object that is created in this statement. This id is only set when the object is already persisted. If not set, this method returns 0.
      Returns:
      the object id or 0 if not set

    • getObjectId

      protected int getObjectId()
      Get the current object id, or get a new id from the database. The object id is used when creating new database object (CREATE statement). This method may be called only once.
      Returns:
      the object id

    • getPlanSQL

      public String getPlanSQL(int sqlFlags)
      Get the SQL statement with the execution plan.
      Parameters:
      sqlFlags - formatting flags
      Returns:
      the execution plan

    • checkCanceled

      public void checkCanceled()
      Check if this statement was canceled.
      Throws:
      DbException - if it was canceled

    • setPersistedObjectId

      public void setPersistedObjectId(int i)
      Set the persisted object id for this statement.
      Parameters:
      i - the object id

    • setSession

      public void setSession(SessionLocal currentSession)
      Set the session for this statement.
      Parameters:
      currentSession - the new session

    • trace

      void trace(long startTimeNanos, long rowCount)
      Print information about the statement executed if info trace level is enabled.
      Parameters:
      startTimeNanos - when the statement was started
      rowCount - the query or update row count

    • setPrepareAlways

      public void setPrepareAlways(boolean prepareAlways)
      Set the prepare always flag. If set, the statement is re-compiled whenever it is executed.
      Parameters:
      prepareAlways - the new value

    • setCurrentRowNumber

      public void setCurrentRowNumber(long rowNumber)
      Set the current row number.
      Parameters:
      rowNumber - the row number

    • getCurrentRowNumber

      public long getCurrentRowNumber()
      Get the current row number.
      Returns:
      the row number

    • setProgress

      private void setProgress()
      Notifies query progress via the DatabaseEventListener

    • toString

      public String toString()
      Convert the statement to a String.
      Overrides:
      toString in class Object
      Returns:
      the SQL statement

    • getSimpleSQL

      public static String getSimpleSQL(Expression[] list)
      Get the SQL snippet of the expression list.
      Parameters:
      list - the expression list
      Returns:
      the SQL snippet

    • setRow

      protected DbException setRow(DbException e, long rowId, String values)
      Set the SQL statement of the exception to the given row.
      Parameters:
      e - the exception
      rowId - the row number
      values - the values of the row
      Returns:
      the exception

    • isCacheable

      public boolean isCacheable()

    • getCteCleanups

      public List<TableView> getCteCleanups()
      Returns:
      the temporary views created for CTE's.

    • setCteCleanups

      public void setCteCleanups(List<TableView> cteCleanups)
      Set the temporary views created for CTE's.
      Parameters:
      cteCleanups - the temporary views

    • getSession

      public final SessionLocal getSession()

    • collectDependencies

      public void collectDependencies(HashSet<DbObject> dependencies)
      Find and collect all DbObjects, this Prepared depends on.
      Parameters:
      dependencies - collection of dependencies to populate