h2 drop column after drop constraint failes - database

Question

Problem:
We try to run your update script in h2 for testing.
With every version we have a update.sql to run the updates on the DB.
But we get a problem when trying to delete a constraint (foreign key):
Error:
Exception in thread "main" org.h2.jdbc.JdbcSQLException: Index "FP_ACL_PERMISSION_UNQ" belongs to constraint "CONSTRAINT_31B"; SQL statement:
ALTER TABLE FP_ACL_PERMISSION DROP INDEX FP_ACL_PERMISSION_UNQ; [90085-191]
at org.h2.message.DbException.getJdbcSQLException(DbException.java:345)
at org.h2.message.DbException.get(DbException.java:179)
at org.h2.command.ddl.DropIndex.update(DropIndex.java:63)
at org.h2.command.CommandContainer.update(CommandContainer.java:98)
at org.h2.command.Command.executeUpdate(Command.java:258)
at org.h2.jdbc.JdbcStatement.executeInternal(JdbcStatement.java:184)
at org.h2.jdbc.JdbcStatement.execute(JdbcStatement.java:158)
at com.rbs.mib.portal.HelloWorld.main(HelloWorld.java:63)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:144)
Code to reproduce the problem:
public class ReproduceH2Problem{
public static void main(String... args) throws Exception {
Class.forName("org.h2.Driver");
Connection conn = DriverManager.getConnection("jdbc:h2:~/test;MODE=ORACLE", "sa", "sa");
Statement stat = conn.createStatement();
stat.execute("DROP ALL OBJECTS");
// init v1.0.0
stat.execute("CREATE TABLE FP_ACL" +
"(" +
" ACL_ID INTEGER NOT NULL," +
" REPORT_KEY VARCHAR2(100) NOT NULL," +
" PARENT_ACL_ID INTEGER" +
");");
stat.execute("CREATE TABLE FP_ACL_PERMISSION" +
"(" +
" PERMISSION_ID INTEGER NOT NULL," +
" ACL_ID INTEGER NOT NULL," +
" NAME VARCHAR2(100)" +
");");
stat.execute("CREATE UNIQUE INDEX FP_ACL_PERMISSION_UNQ ON FP_ACL_PERMISSION" +
"(ACL_ID, NAME);");
stat.execute("ALTER TABLE FP_ACL_PERMISSION ADD " +
"CHECK (ACL_ID IS NOT NULL);");
stat.execute("ALTER TABLE FP_ACL_PERMISSION ADD " +
"PRIMARY KEY " +
"(PERMISSION_ID);");
stat.execute("ALTER TABLE FP_ACL_PERMISSION ADD " +
"CONSTRAINT FP_ACL_PERMISSION_UNQ " +
"UNIQUE (ACL_ID, NAME);");
// !! this seems to be the "bad guy" !!
stat.execute("ALTER TABLE FP_ACL_PERMISSION ADD " +
"FOREIGN KEY (ACL_ID) " +
"REFERENCES FP_ACL (ACL_ID);");
//update v1.0.1
stat.execute("ALTER TABLE FP_ACL_PERMISSION DROP CONSTRAINT FP_ACL_PERMISSION_UNQ;");
//here the problems start
stat.execute("ALTER TABLE FP_ACL_PERMISSION DROP INDEX FP_ACL_PERMISSION_UNQ;");
stat.execute("ALTER TABLE FP_ACL_PERMISSION DROP COLUMN ACL_ID;");
stat.execute("ALTER TABLE FP_ACL_PERMISSION ADD CONSTRAINT FP_ACL_PERMISSION_UNQ UNIQUE (NAME);");
stat.close();
conn.close();
}
}

Answer 1

I had to do a workaround by adding meta commands in the sql scripts as
cannot rename the constraints (h2 does not support)
direct subselect does not work
alter table TABLE_NAME drop constraint
(select unique_index_name
from information_schema.constraints
where table_name='TABLE_NAME' and CONSTRAINT_TYPE='REFERENTIAL' and COLUMN_LIST= ='SHORT_ID')
Workaround:
Meta Command in update.sql script:
--H2-DROP-REFERENCE TABLE::FP_ACL_PERMISSION:: COLUMN::ACL_ID::
ALTER TABLE FP_ACL_PERMISSION DROP INDEX FP_ACL_PERMISSION_UNQ;
Filter meta command in groovy test:
public static enum H2_META_COMMAND {
DROP_REFERENCE("--H2-DROP-REFERENCE")
private String command;
H2_META_COMMAND(String command){
this.command = command
}
String getCommand(){
return command;
}
}
and
/**
* This checks for custom H2 Meta commands to close oracle compatibility gap
* #param sqlCommand a single command
*/
public static void executeH2MetaCommands(String sqlSingleCommand, Statement statement){
if(sqlCommand.contains(H2_META_COMMAND.DROP_REFERENCE.getCommand())){
int tableStart = sqlCommand.indexOf("TABLE::", sqlCommand.indexOf(H2_META_COMMAND.DROP_REFERENCE.getCommand()) + H2_META_COMMAND.DROP_REFERENCE.getCommand().size() ) + 7
String table = sqlCommand.substring(tableStart, sqlCommand.indexOf("::",tableStart))
int colStart = sqlCommand.indexOf("COLUMN::") + 8
String col = sqlCommand.substring(colStart, sqlCommand.indexOf("::",colStart))
ResultSet rs = statement.executeQuery("select CONSTRAINT_NAME from information_schema.constraints where table_name='"+ table+"' and CONSTRAINT_TYPE='REFERENTIAL' and COLUMN_LIST= '"+col+"'")
rs.next()
String constraintName = rs.getString(1)
rs.close()
statement.execute("ALTER TABLE FP_ACL_PERMISSION DROP constraint " + constraintName)
}
}