- java.lang.Object
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- org.hsqldb.jdbc.JDBCParameterMetaData
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- All Implemented Interfaces:
java.sql.ParameterMetaData
,java.sql.Wrapper
public class JDBCParameterMetaData extends java.lang.Object implements java.sql.ParameterMetaData, java.sql.Wrapper
An object that can be used to get information about the types and properties for each parameter marker in aPreparedStatement
object. For some queries and driver implementations, the data that would be returned by aParameterMetaData
object may not be available until thePreparedStatement
has been executed.Some driver implementations may not be able to provide information about the types and properties for each parameter marker in a
CallableStatement
object.- Since:
- JDK 1.4, HSQLDB 1.7.2
- Author:
- Campbell Burnet (campbell-burnet@users dot sourceforge.net)
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description java.lang.String
getParameterClassName(int param)
Retrieves the fully-qualified name of the Java class whose instances should be passed to the methodPreparedStatement.setObject
.int
getParameterCount()
Retrieves the number of parameters in thePreparedStatement
object for which thisParameterMetaData
object contains information.int
getParameterMode(int param)
Retrieves the designated parameter's mode.int
getParameterType(int param)
Retrieves the designated parameter's SQL type.java.lang.String
getParameterTypeName(int param)
Retrieves the designated parameter's database-specific type name.int
getPrecision(int param)
Retrieves the designated parameter's specified column size.int
getScale(int param)
Retrieves the designated parameter's number of digits to right of the decimal point.int
isNullable(int param)
Retrieves whether null values are allowed in the designated parameter.boolean
isSigned(int param)
Retrieves whether values for the designated parameter can be signed numbers.boolean
isWrapperFor(java.lang.Class<?> iface)
Returns true if this either implements the interface argument or is directly or indirectly a wrapper for an object that does.java.lang.String
toString()
Retrieves a String representation of this object.<T> T
unwrap(java.lang.Class<T> iface)
Returns an object that implements the given interface to allow access to non-standard methods, or standard methods not exposed by the proxy.
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Method Detail
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getParameterCount
public int getParameterCount() throws java.sql.SQLException
Retrieves the number of parameters in thePreparedStatement
object for which thisParameterMetaData
object contains information.- Specified by:
getParameterCount
in interfacejava.sql.ParameterMetaData
- Returns:
- the number of parameters
- Throws:
java.sql.SQLException
- if a database access error occurs- Since:
- JDK 1.4, HSQLDB 1.7.2
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isNullable
public int isNullable(int param) throws java.sql.SQLException
Retrieves whether null values are allowed in the designated parameter.- Specified by:
isNullable
in interfacejava.sql.ParameterMetaData
- Parameters:
param
- the first parameter is 1, the second is 2, ...- Returns:
- the nullability status of the given parameter; one of
ParameterMetaData.parameterNoNulls
,ParameterMetaData.parameterNullable
, orParameterMetaData.parameterNullableUnknown
- Throws:
java.sql.SQLException
- if a database access error occurs- Since:
- JDK 1.4, HSQLDB 1.7.2
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isSigned
public boolean isSigned(int param) throws java.sql.SQLException
Retrieves whether values for the designated parameter can be signed numbers.- Specified by:
isSigned
in interfacejava.sql.ParameterMetaData
- Parameters:
param
- the first parameter is 1, the second is 2, ...- Returns:
true
if so;false
otherwise- Throws:
java.sql.SQLException
- if a database access error occurs- Since:
- JDK 1.4, HSQLDB 1.7.2
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getPrecision
public int getPrecision(int param) throws java.sql.SQLException
Retrieves the designated parameter's specified column size.The returned value represents the maximum column size for the given parameter. For numeric data, this is the maximum precision. For character data, this is the length in characters. For datetime datatypes, this is the length in characters of the String representation (assuming the maximum allowed precision of the fractional seconds component). For binary data, this is the length in bytes. For the ROWID datatype, this is the length in bytes. 0 is returned for data types where the column size is not applicable.
- Specified by:
getPrecision
in interfacejava.sql.ParameterMetaData
- Parameters:
param
- the first parameter is 1, the second is 2, ...- Returns:
- precision
- Throws:
java.sql.SQLException
- if a database access error occurs- Since:
- JDK 1.4, HSQLDB 1.7.2
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getScale
public int getScale(int param) throws java.sql.SQLException
Retrieves the designated parameter's number of digits to right of the decimal point. 0 is returned for data types where the scale is not applicable.- Specified by:
getScale
in interfacejava.sql.ParameterMetaData
- Parameters:
param
- the first parameter is 1, the second is 2, ...- Returns:
- scale
- Throws:
java.sql.SQLException
- if a database access error occurs- Since:
- JDK 1.4, HSQLDB 1.7.2
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getParameterType
public int getParameterType(int param) throws java.sql.SQLException
Retrieves the designated parameter's SQL type.- Specified by:
getParameterType
in interfacejava.sql.ParameterMetaData
- Parameters:
param
- the first parameter is 1, the second is 2, ...- Returns:
- SQL type from
java.sql.Types
- Throws:
java.sql.SQLException
- if a database access error occurs- Since:
- JDK 1.4, HSQLDB 1.7.2
- See Also:
Types
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getParameterTypeName
public java.lang.String getParameterTypeName(int param) throws java.sql.SQLException
Retrieves the designated parameter's database-specific type name.- Specified by:
getParameterTypeName
in interfacejava.sql.ParameterMetaData
- Parameters:
param
- the first parameter is 1, the second is 2, ...- Returns:
- type the name used by the database. If the parameter type is a user-defined type, then a fully-qualified type name is returned.
- Throws:
java.sql.SQLException
- if a database access error occurs- Since:
- JDK 1.4, HSQLDB 1.7.2
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getParameterClassName
public java.lang.String getParameterClassName(int param) throws java.sql.SQLException
Retrieves the fully-qualified name of the Java class whose instances should be passed to the methodPreparedStatement.setObject
.- Specified by:
getParameterClassName
in interfacejava.sql.ParameterMetaData
- Parameters:
param
- the first parameter is 1, the second is 2, ...- Returns:
- the fully-qualified name of the class in the Java programming
language that would be used by the method
PreparedStatement.setObject
to set the value in the specified parameter. This is the class name used for custom mapping. - Throws:
java.sql.SQLException
- if a database access error occurs- Since:
- JDK 1.4, HSQLDB 1.7.2
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getParameterMode
public int getParameterMode(int param) throws java.sql.SQLException
Retrieves the designated parameter's mode.- Specified by:
getParameterMode
in interfacejava.sql.ParameterMetaData
- Parameters:
param
- the first parameter is 1, the second is 2, ...- Returns:
- mode of the parameter; one of
ParameterMetaData.parameterModeIn
,ParameterMetaData.parameterModeOut
, orParameterMetaData.parameterModeInOut
ParameterMetaData.parameterModeUnknown
. - Throws:
java.sql.SQLException
- if a database access error occurs- Since:
- JDK 1.4, HSQLDB 1.7.2
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unwrap
public <T> T unwrap(java.lang.Class<T> iface) throws java.sql.SQLException
Returns an object that implements the given interface to allow access to non-standard methods, or standard methods not exposed by the proxy. If the receiver implements the interface then the result is the receiver or a proxy for the receiver. If the receiver is a wrapper and the wrapped object implements the interface then the result is the wrapped object or a proxy for the wrapped object. Otherwise return the result of callingunwrap
recursively on the wrapped object or a proxy for that result. If the receiver is not a wrapper and does not implement the interface, then anSQLException
is thrown.- Specified by:
unwrap
in interfacejava.sql.Wrapper
- Parameters:
iface
- A Class defining an interface that the result must implement.- Returns:
- an object that implements the interface. May be a proxy for the actual implementing object.
- Throws:
java.sql.SQLException
- If no object found that implements the interface- Since:
- JDK 1.6, HSQLDB 2.0
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isWrapperFor
public boolean isWrapperFor(java.lang.Class<?> iface) throws java.sql.SQLException
Returns true if this either implements the interface argument or is directly or indirectly a wrapper for an object that does. Returns false otherwise. If this implements the interface then return true, else if this is a wrapper then return the result of recursively callingisWrapperFor
on the wrapped object. If this does not implement the interface and is not a wrapper, return false. This method should be implemented as a low-cost operation compared tounwrap
so that callers can use this method to avoid expensiveunwrap
calls that may fail. If this method returns true then callingunwrap
with the same argument should succeed.- Specified by:
isWrapperFor
in interfacejava.sql.Wrapper
- Parameters:
iface
- a Class defining an interface.- Returns:
- true if this implements the interface or directly or indirectly wraps an object that does.
- Throws:
java.sql.SQLException
- if an error occurs while determining whether this is a wrapper for an object with the given interface.- Since:
- JDK 1.6, HSQLDB 2.0
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toString
public java.lang.String toString()
Retrieves a String representation of this object.- Overrides:
toString
in classjava.lang.Object
- Returns:
- a String representation of this object
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