EmbedResultSetMetaData (Apache Derby V10.14 Internals)

java.lang.Object
- org.apache.derby.impl.jdbc.EmbedResultSetMetaData

All Implemented Interfaces:

java.sql.ResultSetMetaData, java.sql.Wrapper
```
public class EmbedResultSetMetaData
extends java.lang.Object
implements java.sql.ResultSetMetaData
```
A ResultSetMetaData object can be used to find out about the types and properties of the columns in a ResultSet.
We take the (Derby) ResultDescription and examine it, to return the appropriate information.
This class can be used outside of this package to convert a ResultDescription into a ResultSetMetaData object.
EmbedResultSetMetaData objects are shared across multiple threads by being stored in the ResultDescription for a compiled plan. If the required api for ResultSetMetaData ever changes so that it has a close() method, a getConnection() method or any other Connection or ResultSet specific method then this sharing must be removed.

Field Summary

Fields
Modifier and Type Field Description

private ResultColumnDescriptor[] columnInfo
- Fields inherited from interface java.sql.ResultSetMetaData
  columnNoNulls, columnNullable, columnNullableUnknown

Fields
Modifier and Type	Field	Description
`private ResultColumnDescriptor[]`	`columnInfo`

Constructor Summary

Constructors
Constructor Description

EmbedResultSetMetaData(ResultColumnDescriptor[] columnInfo)

Constructors
Constructor	Description
`EmbedResultSetMetaData(ResultColumnDescriptor[] columnInfo)`

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`java.lang.String`	`getCatalogName(int column)`	What's a column's table's catalog name?
`java.lang.String`	`getColumnClassName(int column)`	JDBC 2.0
`int`	`getColumnCount()`	What's the number of columns in the ResultSet?
`int`	`getColumnDisplaySize(int column)`	What's the column's normal max width in chars?
`java.lang.String`	`getColumnLabel(int column)`	What's the suggested column title for use in printouts and displays?
`java.lang.String`	`getColumnName(int column)`	What's a column's name?
`int`	`getColumnType(int column)`	What's a column's SQL type?
`private DataTypeDescriptor`	`getColumnTypeDescriptor(int column)`
`java.lang.String`	`getColumnTypeName(int column)`	What's a column's data source specific type name?
`int`	`getPrecision(int column)`	What's a column's number of decimal digits?
`static ResultColumnDescriptor`	`getResultColumnDescriptor(java.lang.String name, int jdcbTypeId, boolean nullable)`
`static ResultColumnDescriptor`	`getResultColumnDescriptor(java.lang.String name, int jdcbTypeId, boolean nullable, int length)`
`static ResultColumnDescriptor`	`getResultColumnDescriptor(java.lang.String name, DataTypeDescriptor dtd)`
`int`	`getScale(int column)`	What's a column's number of digits to right of the decimal point?
`java.lang.String`	`getSchemaName(int column)`	What's a column's table's schema?
`java.lang.String`	`getTableName(int column)`	What's a column's table name?
`boolean`	`isAutoIncrement(int column)`	Is the column automatically numbered, thus read-only?
`boolean`	`isCaseSensitive(int column)`	Does a column's case matter?
`boolean`	`isCurrency(int column)`	Is the column a cash value?
`boolean`	`isDefinitelyWritable(int column)`	Will a write on the column definitely succeed?
`int`	`isNullable(int column)`	Can you put a NULL in this column?
`boolean`	`isReadOnly(int column)`	Is a column definitely not writable?
`boolean`	`isSearchable(int column)`	Can the column be used in a where clause?
`boolean`	`isSigned(int column)`	Is the column a signed number?
`boolean`	`isWrapperFor(java.lang.Class<?> iface)`	Returns whether or not this instance implements the specified interface.
`boolean`	`isWritable(int column)`	Is it possible for a write on the column to succeed?
`<T> T`	`unwrap(java.lang.Class<T> iface)`	Returns `this` if this class implements the interface.
`private void`	`validColumnNumber(int column)`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - columnInfo
```
private final ResultColumnDescriptor[] columnInfo
```
- Constructor Detail
  - EmbedResultSetMetaData
```
public EmbedResultSetMetaData(ResultColumnDescriptor[] columnInfo)
```
- Method Detail
  - getColumnCount
```
public final int getColumnCount()
```
    What's the number of columns in the ResultSet?
    
    Specified by:
    
    getColumnCount in interface java.sql.ResultSetMetaData
    
    Returns:
    
    the number
  - isAutoIncrement
```
public final boolean isAutoIncrement(int column)
                              throws java.sql.SQLException
```
    Is the column automatically numbered, thus read-only?
    
    Specified by:
    
    isAutoIncrement in interface java.sql.ResultSetMetaData
    
    Parameters:
    
    column - the first column is 1, the second is 2, ...
    
    Returns:
    
    true if so
    
    Throws:
    
    java.sql.SQLException - thrown on failure
  - isCaseSensitive
```
public final boolean isCaseSensitive(int column)
                              throws java.sql.SQLException
```
    Does a column's case matter?
    
    Specified by:
    
    isCaseSensitive in interface java.sql.ResultSetMetaData
    
    Parameters:
    
    column - the first column is 1, the second is 2, ...
    
    Returns:
    
    true if so
    
    Throws:
    
    java.sql.SQLException - thrown on failure
  - isSearchable
```
public final boolean isSearchable(int column)
                           throws java.sql.SQLException
```
    Can the column be used in a where clause?
    
    Specified by:
    
    isSearchable in interface java.sql.ResultSetMetaData
    
    Parameters:
    
    column - the first column is 1, the second is 2, ...
    
    Returns:
    
    true if so
    
    Throws:
    
    java.sql.SQLException - thrown on failure
  - isCurrency
```
public final boolean isCurrency(int column)
                         throws java.sql.SQLException
```
    Is the column a cash value? Always returns false since there are no currency data types in Derby.
    
    Specified by:
    
    isCurrency in interface java.sql.ResultSetMetaData
    
    Parameters:
    
    column - the first column is 1, the second is 2, ...
    
    Returns:
    
    false, always
    
    Throws:
    
    java.sql.SQLException - thrown on failure
  - isNullable
```
public final int isNullable(int column)
                     throws java.sql.SQLException
```
    Can you put a NULL in this column?
    
    Specified by:
    
    isNullable in interface java.sql.ResultSetMetaData
    
    Parameters:
    
    column - the first column is 1, the second is 2, ...
    
    Returns:
    
    columnNoNulls, columnNullable or columnNullableUnknown
    
    Throws:
    
    java.sql.SQLException - thrown on failure
  - isSigned
```
public final boolean isSigned(int column)
                       throws java.sql.SQLException
```
    Is the column a signed number?
    
    Specified by:
    
    isSigned in interface java.sql.ResultSetMetaData
    
    Parameters:
    
    column - the first column is 1, the second is 2, ...
    
    Returns:
    
    true if so
    
    Throws:
    
    java.sql.SQLException - thrown on failure
  - getColumnDisplaySize
```
public final int getColumnDisplaySize(int column)
                               throws java.sql.SQLException
```
    What's the column's normal max width in chars?
    
    Specified by:
    
    getColumnDisplaySize in interface java.sql.ResultSetMetaData
    
    Parameters:
    
    column - the first column is 1, the second is 2, ...
    
    Returns:
    
    max width
    
    Throws:
    
    java.sql.SQLException - thrown on failure
  - getColumnLabel
```
public final java.lang.String getColumnLabel(int column)
                                      throws java.sql.SQLException
```
    What's the suggested column title for use in printouts and displays?
    
    Specified by:
    
    getColumnLabel in interface java.sql.ResultSetMetaData
    
    Parameters:
    
    column - the first column is 1, the second is 2, ...
    
    Returns:
    
    true if so
    
    Throws:
    
    java.sql.SQLException - thrown on failure
  - getColumnName
```
public final java.lang.String getColumnName(int column)
                                     throws java.sql.SQLException
```
    What's a column's name?
    
    Specified by:
    
    getColumnName in interface java.sql.ResultSetMetaData
    
    Parameters:
    
    column - the first column is 1, the second is 2, ...
    
    Returns:
    
    column name
    
    Throws:
    
    java.sql.SQLException - thrown on failure
  - getSchemaName
```
public final java.lang.String getSchemaName(int column)
                                     throws java.sql.SQLException
```
    What's a column's table's schema?
    
    Specified by:
    
    getSchemaName in interface java.sql.ResultSetMetaData
    
    Parameters:
    
    column - the first column is 1, the second is 2, ...
    
    Returns:
    
    schema name or "" if not applicable
    
    Throws:
    
    java.sql.SQLException - thrown on failure
  - getPrecision
```
public final int getPrecision(int column)
                       throws java.sql.SQLException
```
    What's a column's number of decimal digits?
    
    Specified by:
    
    getPrecision in interface java.sql.ResultSetMetaData
    
    Parameters:
    
    column - the first column is 1, the second is 2, ...
    
    Returns:
    
    precision
    
    Throws:
    
    java.sql.SQLException - thrown on failure
  - getScale
```
public final int getScale(int column)
                   throws java.sql.SQLException
```
    What's a column's number of digits to right of the decimal point?
    
    Specified by:
    
    getScale in interface java.sql.ResultSetMetaData
    
    Parameters:
    
    column - the first column is 1, the second is 2, ...
    
    Returns:
    
    scale
    
    Throws:
    
    java.sql.SQLException - thrown on failure
  - getTableName
```
public final java.lang.String getTableName(int column)
                                    throws java.sql.SQLException
```
    What's a column's table name?
    
    Specified by:
    
    getTableName in interface java.sql.ResultSetMetaData
    
    Returns:
    
    table name or "" if not applicable
    
    Throws:
    
    java.sql.SQLException - thrown on failure
  - getCatalogName
```
public final java.lang.String getCatalogName(int column)
                                      throws java.sql.SQLException
```
    What's a column's table's catalog name?
    
    Specified by:
    
    getCatalogName in interface java.sql.ResultSetMetaData
    
    Parameters:
    
    column - the first column is 1, the second is 2, ...
    
    Returns:
    
    column name or "" if not applicable.
    
    Throws:
    
    java.sql.SQLException - thrown on failure
  - getColumnType
```
public final int getColumnType(int column)
                        throws java.sql.SQLException
```
    What's a column's SQL type?
    
    Specified by:
    
    getColumnType in interface java.sql.ResultSetMetaData
    
    Parameters:
    
    column - the first column is 1, the second is 2, ...
    
    Returns:
    
    SQL type
    
    Throws:
    
    java.sql.SQLException - thrown on failure
    
    See Also:
    
    Types
  - getColumnTypeName
```
public final java.lang.String getColumnTypeName(int column)
                                         throws java.sql.SQLException
```
    What's a column's data source specific type name?
    
    Specified by:
    
    getColumnTypeName in interface java.sql.ResultSetMetaData
    
    Parameters:
    
    column - the first column is 1, the second is 2, ...
    
    Returns:
    
    type name
    
    Throws:
    
    java.sql.SQLException - thrown on failure
  - isReadOnly
```
public final boolean isReadOnly(int column)
                         throws java.sql.SQLException
```
    Is a column definitely not writable?
    
    Specified by:
    
    isReadOnly in interface java.sql.ResultSetMetaData
    
    Parameters:
    
    column - the first column is 1, the second is 2, ...
    
    Returns:
    
    true if so
    
    Throws:
    
    java.sql.SQLException - thrown on failure
  - isWritable
```
public final boolean isWritable(int column)
                         throws java.sql.SQLException
```
    Is it possible for a write on the column to succeed?
    
    Specified by:
    
    isWritable in interface java.sql.ResultSetMetaData
    
    Parameters:
    
    column - the first column is 1, the second is 2, ...
    
    Returns:
    
    true if so
    
    Throws:
    
    java.sql.SQLException - thrown on failure
  - isDefinitelyWritable
```
public final boolean isDefinitelyWritable(int column)
                                   throws java.sql.SQLException
```
    Will a write on the column definitely succeed?
    
    Specified by:
    
    isDefinitelyWritable in interface java.sql.ResultSetMetaData
    
    Parameters:
    
    column - the first column is 1, the second is 2, ...
    
    Returns:
    
    true if so
    
    Throws:
    
    java.sql.SQLException - thrown on failure
  - validColumnNumber
```
private void validColumnNumber(int column)
                        throws java.sql.SQLException
```
    Throws:
    
    java.sql.SQLException
  - getColumnTypeDescriptor
```
private DataTypeDescriptor getColumnTypeDescriptor(int column)
                                            throws java.sql.SQLException
```
    Throws:
    
    java.sql.SQLException
  - getColumnClassName
```
public final java.lang.String getColumnClassName(int column)
                                          throws java.sql.SQLException
```
    JDBC 2.0
    Return the fully qualified name of the Java class whose instances are manufactured if ResultSet.getObject() is called to retrieve a value from the column. ResultSet.getObject() may return a subClass of the class returned by this method.
    
    Specified by:
    
    getColumnClassName in interface java.sql.ResultSetMetaData
    
    Throws:
    
    java.sql.SQLException - Feature not inplemented for now.
  - getResultColumnDescriptor
```
public static ResultColumnDescriptor getResultColumnDescriptor(java.lang.String name,
                                                               int jdcbTypeId,
                                                               boolean nullable)
```
  - getResultColumnDescriptor
```
public static ResultColumnDescriptor getResultColumnDescriptor(java.lang.String name,
                                                               int jdcbTypeId,
                                                               boolean nullable,
                                                               int length)
```
  - getResultColumnDescriptor
```
public static ResultColumnDescriptor getResultColumnDescriptor(java.lang.String name,
                                                               DataTypeDescriptor dtd)
```
  - isWrapperFor
```
public final boolean isWrapperFor(java.lang.Class<?> iface)
```
    Returns whether or not this instance implements the specified interface.
    
    Specified by:
    
    isWrapperFor in interface java.sql.Wrapper
    
    Parameters:
    
    iface - the interface to check for
    
    Returns:
    
    true if this implements the interface
  - unwrap
```
public final <T> T unwrap(java.lang.Class<T> iface)
                   throws java.sql.SQLException
```
    Returns this if this class implements the interface.
    
    Specified by:
    
    unwrap in interface java.sql.Wrapper
    
    Parameters:
    
    iface - the interface
    
    Returns:
    
    an object that implements the interface
    
    Throws:
    
    java.sql.SQLException - if no object is found that implements the interface

Class EmbedResultSetMetaData

Field Summary

Fields inherited from interface java.sql.ResultSetMetaData

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

columnInfo

Constructor Detail

EmbedResultSetMetaData

Method Detail

getColumnCount

isAutoIncrement

isCaseSensitive

isSearchable

isCurrency

isNullable

isSigned

getColumnDisplaySize

getColumnLabel

getColumnName

getSchemaName

getPrecision

getScale

getTableName

getCatalogName

getColumnType

getColumnTypeName

isReadOnly

isWritable

isDefinitelyWritable

validColumnNumber

getColumnTypeDescriptor

getColumnClassName

getResultColumnDescriptor

getResultColumnDescriptor

getResultColumnDescriptor

isWrapperFor

unwrap