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public interface Aggregate
A user-defined aggregate function needs to implement this interface. The class must be public and must have a public non-argument constructor.
Method Summary | |
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void |
add(java.lang.Object value)
This method is called once for each row. |
int |
getInternalType(int[] inputTypes)
This method must return the H2 data type, Value ,
of the aggregate function, given the H2 data type of the input data. |
java.lang.Object |
getResult()
This method returns the computed aggregate value. |
void |
init(java.sql.Connection conn)
This method is called when the aggregate function is used. |
Method Detail |
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void init(java.sql.Connection conn) throws java.sql.SQLException
conn
- a connection to the database
java.sql.SQLException
int getInternalType(int[] inputTypes) throws java.sql.SQLException
Value
,
of the aggregate function, given the H2 data type of the input data.
The method should check here if the number of parameters
passed is correct, and if not it should throw an exception.
inputTypes
- the H2 data type of the parameters,
java.sql.SQLException
- if the number/type of parameters passed is incorrectvoid add(java.lang.Object value) throws java.sql.SQLException
value
- the value(s) for this row
java.sql.SQLException
java.lang.Object getResult() throws java.sql.SQLException
java.sql.SQLException
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