[
https://issues.apache.org/jira/browse/DERBY-3181?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15270231#comment-15270231
]
Danoja Dias commented on DERBY-3181:
------------------------------------
In the first case of repro.java
it runs following query for getBestRowIdentifier method,
getBestRowIdentifierAllColumns=\
SELECT \
CAST (java.sql.DatabaseMetaData::bestRowSession AS SMALLINT) AS
SCOPE, \
COLS.COLUMNNAME AS COLUMN_NAME, \
COLS.COLUMNDATATYPE.getJDBCTypeId() AS DATA_TYPE, \
CAST (COLS.COLUMNDATATYPE.getTypeName() AS VARCHAR(128)) AS
TYPE_NAME, \
COLS.COLUMNDATATYPE.getMaximumWidth() AS COLUMN_SIZE, \
CAST (NULL AS INT) AS BUFFER_LENGTH, \
CAST ((CASE WHEN (COLS.COLUMNDATATYPE.getJDBCTypeId() IN ( \
java.sql.Types::DECIMAL, java.sql.Types::NUMERIC, \
java.sql.Types::INTEGER, java.sql.Types::SMALLINT, \
java.sql.Types::TINYINT, java.sql.Types::BIGINT, \
java.sql.Types::DATE, java.sql.Types::TIME, \
java.sql.Types::TIMESTAMP)) \
THEN COLS.COLUMNDATATYPE.getPrecision() \
ELSE CAST (NULL AS SMALLINT) END) AS SMALLINT) \
AS DECIMAL_DIGITS, \
CAST (java.sql.DatabaseMetaData::bestRowNotPseudo AS SMALLINT)
AS PSEUDO_COLUMN \
FROM SYS.SYSSCHEMAS SCHEMAS, SYS.SYSTABLES TABS, \
SYS.SYSCOLUMNS COLS \
WHERE COLS.REFERENCEID = TABS.TABLEID \
AND TABS.SCHEMAID = SCHEMAS.SCHEMAID \
AND ((1=1) OR % IS NOT NULL) \
AND (SCHEMAS.SCHEMANAME LIKE APP) \
AND (TABS.TABLENAME=a) \
AND 1 BETWEEN 0 AND 2 \
AND (1<>0 OR NOT COLS.COLUMNDATATYPE.isNullable())
> isNullable on ResultSetMetaData from DatabaseMetaData.getBestRowIdentifier
> values are opposite when there is no rows in ResultSet vs. when there is a
> row.
> ----------------------------------------------------------------------------------------------------------------------------------------------------------
>
> Key: DERBY-3181
> URL: https://issues.apache.org/jira/browse/DERBY-3181
> Project: Derby
> Issue Type: Bug
> Components: JDBC
> Affects Versions: 10.4.1.3
> Reporter: Myrna van Lunteren
> Assignee: Danoja Dias
> Priority: Trivial
> Labels: derby_triage10_5_2
> Attachments: repro.java
>
>
> With code like the following:
> DatabaseMetaData dmd = conn.getMetaData();
> ResultSet rs = dmd.getBestRowIdentifier(null,"APP","a",3,true);
> ResultSetMetaData rsmd = rs.getMetaData();
> int actualCols = rsmd.getColumnCount();
> for (int i = 0; i < actualCols; i++)
> {
> System.out.print("getColumnName: " + rsmd.getColumnName(i+1)
> + ", isNullable: ");
> System.out.println(rsmd.isNullable(i+1));
> }
> The printed values for isNullable returned are opposite of what they are when
> the getBestRowIdentifier call looks like this:
> ResultSet rs = dmd.getBestRowIdentifier(null,"APP","a",1,true);
> In the latter case, the values are:
> getColumnName: SCOPE, isNullable: 0
> getColumnName: COLUMN_NAME, isNullable: 1
> getColumnName: DATA_TYPE, isNullable: 0
> getColumnName: TYPE_NAME, isNullable: 1
> getColumnName: COLUMN_SIZE, isNullable: 0
> getColumnName: BUFFER_LENGTH, isNullable: 0
> getColumnName: DECIMAL_DIGITS, isNullable: 0
> getColumnName: PSEUDO_COLUMN, isNullable: 0
> In the first case, the values are:
> getColumnName: SCOPE, isNullable: 1
> getColumnName: COLUMN_NAME, isNullable: 0
> getColumnName: DATA_TYPE, isNullable: 1
> getColumnName: TYPE_NAME, isNullable: 1
> getColumnName: COLUMN_SIZE, isNullable: 1
> getColumnName: BUFFER_LENGTH, isNullable: 1
> getColumnName: DECIMAL_DIGITS, isNullable: 1
> getColumnName: PSEUDO_COLUMN, isNullable: 1
> The isNullable value should be stable.
> It's probably worthwhile verifying what the value *should* be in the first
> place.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
