Package org.h2.command
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
A prepared statement.
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Field Summary
FieldsModifier and TypeFieldDescriptionprivate Command
protected boolean
Whether to create a new object (for indexes).Common table expressions (CTE) in queries require us to create temporary views, which need to be cleaned up once a command is done executing.private long
private long
The list of parameters.private int
Used to preserve object identities on database startup.protected boolean
If the query should be prepared before each execution.private int
protected SessionLocal
The session.protected String
The SQL string.The SQL tokens. -
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionvoid
Check if this statement was canceled.protected void
Check if all parameters have been set.void
collectDependencies
(HashSet<DbObject> dependencies) Find and collect all DbObjects, this Prepared depends on.long
Get the current row number.(package private) long
Get the meta data modification id of the database when this statement was compiled.protected int
Get the current object id, or get a new id from the database.Get the parameter list.int
Get the object id to use for the database object that is created in this statement.getPlanSQL
(int sqlFlags) Get the SQL statement with the execution plan.final SessionLocal
static String
getSimpleSQL
(Expression[] list) Get the SQL snippet of the expression list.final String
getSQL()
Get the SQL statement.Get the SQL tokens.abstract int
getType()
Get the command type as defined in CommandInterfaceboolean
boolean
isQuery()
Check if this object is a query.boolean
Check if this command is read only.abstract boolean
Check if this command is transactional.boolean
Check if the statement needs to be re-compiled.void
prepare()
Prepare this statement.query
(long maxrows) Execute the query.abstract ResultInterface
Get an empty result set containing the meta data.void
setCommand
(Command command) Set the command.void
setCteCleanups
(List<TableView> cteCleanups) Set the temporary views created for CTE's.void
setCurrentRowNumber
(long rowNumber) Set the current row number.(package private) void
setModificationMetaId
(long id) Set the meta data modification id of this statement.void
setParameterList
(ArrayList<Parameter> parameters) Set the parameter list of this statement.void
setPersistedObjectId
(int i) Set the persisted object id for this statement.void
setPrepareAlways
(boolean prepareAlways) Set the prepare always flag.private void
Notifies query progress via the DatabaseEventListenerprotected DbException
setRow
(DbException e, long rowId, String values) Set the SQL statement of the exception to the given row.void
setSession
(SessionLocal currentSession) Set the session for this statement.final void
Set the SQL statement.toString()
Convert the statement to a String.(package private) void
trace
(long startTimeNanos, long rowCount) Print information about the statement executed if info trace level is enabled.long
update()
Execute the statement.
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Field Details
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session
The session. -
sqlStatement
The SQL string. -
sqlTokens
The SQL tokens. -
create
protected boolean createWhether to create a new object (for indexes). -
parameters
The list of parameters. -
prepareAlways
protected boolean prepareAlwaysIf 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
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persistedObjectId
private int persistedObjectIdUsed 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
Common table expressions (CTE) in queries require us to create temporary views, which need to be cleaned up once a command is done executing.
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Constructor Details
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Prepared
Create a new object.- Parameters:
session
- the session
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Method Details
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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
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queryMeta
Get an empty result set containing the meta data.- Returns:
- the result set
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getType
public abstract int getType()Get the command type as defined in CommandInterface- Returns:
- the statement type
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isReadOnly
public boolean isReadOnly()Check if this command is read only.- Returns:
- true if it is
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needRecompile
public boolean needRecompile()Check if the statement needs to be re-compiled.- Returns:
- true if it must
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getModificationMetaId
long getModificationMetaId()Get the meta data modification id of the database when this statement was compiled.- Returns:
- the meta data modification id
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setModificationMetaId
void setModificationMetaId(long id) Set the meta data modification id of this statement.- Parameters:
id
- the new id
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setParameterList
Set the parameter list of this statement.- Parameters:
parameters
- the parameter list
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getParameters
Get the parameter list.- Returns:
- the parameter list
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checkParameters
protected void checkParameters()Check if all parameters have been set.- Throws:
DbException
- if any parameter has not been set
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setCommand
Set the command.- Parameters:
command
- the new command
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isQuery
public boolean isQuery()Check if this object is a query.- Returns:
- true if it is
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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
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query
Execute the query.- Parameters:
maxrows
- the maximum number of rows to return- Returns:
- the result set
- Throws:
DbException
- if it is not a query
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setSQL
Set the SQL statement.- Parameters:
sql
- the SQL statementsqlTokens
- the SQL tokens
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getSQL
Get the SQL statement.- Returns:
- the SQL statement
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getSQLTokens
Get the SQL tokens.- Returns:
- the SQL tokens
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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
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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
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getPlanSQL
Get the SQL statement with the execution plan.- Parameters:
sqlFlags
- formatting flags- Returns:
- the execution plan
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checkCanceled
public void checkCanceled()Check if this statement was canceled.- Throws:
DbException
- if it was canceled
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setPersistedObjectId
public void setPersistedObjectId(int i) Set the persisted object id for this statement.- Parameters:
i
- the object id
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setSession
Set the session for this statement.- Parameters:
currentSession
- the new session
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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 startedrowCount
- the query or update row count
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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
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setCurrentRowNumber
public void setCurrentRowNumber(long rowNumber) Set the current row number.- Parameters:
rowNumber
- the row number
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getCurrentRowNumber
public long getCurrentRowNumber()Get the current row number.- Returns:
- the row number
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setProgress
private void setProgress()Notifies query progress via the DatabaseEventListener -
toString
Convert the statement to a String. -
getSimpleSQL
Get the SQL snippet of the expression list.- Parameters:
list
- the expression list- Returns:
- the SQL snippet
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setRow
Set the SQL statement of the exception to the given row.- Parameters:
e
- the exceptionrowId
- the row numbervalues
- the values of the row- Returns:
- the exception
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isCacheable
public boolean isCacheable() -
getCteCleanups
- Returns:
- the temporary views created for CTE's.
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setCteCleanups
Set the temporary views created for CTE's.- Parameters:
cteCleanups
- the temporary views
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getSession
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collectDependencies
Find and collect all DbObjects, this Prepared depends on.- Parameters:
dependencies
- collection of dependencies to populate
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