Обсуждение: PreparedStatement.setXXX
We're moving from Postgresql7.4 to v.8.0.3,
with some problems rising from the strictness of the new driver
postgresql-8.0-311.jdbc3.jar.
We used to call a function f(integer[]) using
PreparedStatement.setString('{...}')
but now the types are not compatible.
How should we fix that ?
A. Using the setArray method :
This requires the implementation of the interface java.sql.Array :
- which methods are required in this case ?
- is there any available implementation of this class ? :)
B. Using the setObject(colnumber, String, type ) method :
This should require less implementation than the Array, shouldn't it ?
- how to specify the type int[] ?
C. Using different drivers / protocol versions / ...
Thanks,
Roberta
Roberta,
You can force version 2 protocol with protocolVersion=2
or you can implement the Array interface.
For putting information into the db, I would imagine all you need to implement is everything up to getResultSet()
Dave
On 18-Jul-05, at 7:55 AM, Roberta Campo wrote:
We're moving from Postgresql7.4 to v.8.0.3,with some problems rising from the strictness of the new driverpostgresql-8.0-311.jdbc3.jar.We used to call a function f(integer[]) usingPreparedStatement.setString('{...}')but now the types are not compatible.How should we fix that ?A. Using the setArray method :This requires the implementation of the interface java.sql.Array :- which methods are required in this case ?- is there any available implementation of this class ? :)B. Using the setObject(colnumber, String, type ) method :This should require less implementation than the Array, shouldn't it ?- how to specify the type int[] ?C. Using different drivers / protocol versions / ...Thanks,Roberta---------------------------(end of broadcast)---------------------------TIP 6: explain analyze is your friend
Roberta:
Here is my utility code that implements java.sql.Array:
public static Array convertStringToPgSqlArray(final String[] s) throws Exception {
if(s == null || s.length < 1) return null;
Array a = new Array() {
public String getBaseTypeName() {return "text";}
public int getBaseType() {return 0;}
public Object getArray() {return null;}
public Object getArray(Map<String, Class<?>> map) {return null;}
public Object getArray(long index, int count) {return null;}
public Object getArray(long index, int count, Map<String, Class<?>> map) {return null;}
public ResultSet getResultSet() {return null;}
public ResultSet getResultSet(Map<String, Class<?>> map) {return null;}
public ResultSet getResultSet(long index, int count) {return null;}
public ResultSet getResultSet(long index, int count, Map<String, Class<?>> map) {return null;}
public String toString() {
String p = "{";
if(s.length == 0) {
} else {
for(int i = 0; i < s.length - 1; i++) p += s[i] + ",";
p += "'" + s[s.length - 1] + "'";
}
p+="}";
return p;
}
};
return a;
}
public static Array convertIntegerToPgSqlArray(final int[] p) {
if(p == null || p.length < 1) return null;
Array a = new Array() {
public String getBaseTypeName() {return "int4";}
public int getBaseType() {return 0;}
public Object getArray() {return null;}
public Object getArray(Map<String, Class<?>> map) {return null;}
public Object getArray(long index, int count) {return null;}
public Object getArray(long index, int count, Map<String, Class<?>> map) {return null;}
public ResultSet getResultSet() {return null;}
public ResultSet getResultSet(Map<String, Class<?>> map) {return null;}
public ResultSet getResultSet(long index, int count) {return null;}
public ResultSet getResultSet(long index, int count, Map<String, Class<?>> map) {return null;}
public String toString() {
String fp = "{";
if(p.length == 0) {
} else {
for(int i = 0; i < p.length - 1; i++) fp += p[i] + ",";
fp += p[p.length - 1];
}
fp+="}";
return fp;
}
};
return a;
}
On Jul 18, 2005, at 6:52 AM, Dave Cramer wrote:
Roberta,You can force version 2 protocol with protocolVersion=2or you can implement the Array interface.For putting information into the db, I would imagine all you need to implement is everything up to getResultSet()DaveOn 18-Jul-05, at 7:55 AM, Roberta Campo wrote:We're moving from Postgresql7.4 to v.8.0.3,with some problems rising from the strictness of the new driverpostgresql-8.0-311.jdbc3.jar.We used to call a function f(integer[]) usingPreparedStatement.setString('{...}')but now the types are not compatible.How should we fix that ?A. Using the setArray method :This requires the implementation of the interface java.sql.Array :- which methods are required in this case ?- is there any available implementation of this class ? :)B. Using the setObject(colnumber, String, type ) method :This should require less implementation than the Array, shouldn't it ?- how to specify the type int[] ?C. Using different drivers / protocol versions / ...Thanks,Roberta---------------------------(end of broadcast)---------------------------TIP 6: explain analyze is your friend
Roberta Campo wrote:
> A. Using the setArray method :
> This requires the implementation of the interface java.sql.Array :
> - which methods are required in this case ?
> - is there any available implementation of this class ? :)
Someone else replied to this with an implementation..
The driver's Array support is pretty bad currently. It will only work if
the Array implementation implements:
- getBaseTypeName() returns the underlying postgresql type name ("int")
- toString() returns a correctly-formatted array string ("{1,2,3}")
Proper support for arbitrary Array implementations (and bare arrays via
setObject) has been on my todo list for ages but it's no longer a high
priority for our application so I doubt I'll work on it any time soon :/
> B. Using the setObject(colnumber, String, type ) method :
> This should require less implementation than the Array, shouldn't it ?
> - how to specify the type int[] ?
JDBC has no mechanism to specify a particular array type via a Types.*
constant unfortunately :(
> C. Using different drivers / protocol versions / ...
Using protocol version 2 as Dave Cramer suggests is a short-term fix but
you don't want to be using that in the longer term..
-O