A tool for testing SQL database management systems with automatic dialect adaptability.

Requirements:

• Java 11 or above
• Maven (sudo apt install maven on Ubuntu)
• The DBMS that you want to test (embedded DBMSs such as DuckDB, H2, and SQLite do not require a setup)

# unzip the file first then get into the directory
cd sqlancer
mvn package -DskipTests
java -jar target/sqlancer-2.0.0.jar --use-reducer general  --database-engine sqlite

If the execution prints progress information every five seconds, then the tool works as expected. Note that SQLancer++ might find bugs in SQLite. Before reporting these, be sure to check that they can still be reproduced when using the latest development version. The shortcut CTRL+C can be used to terminate SQLancer++ manually. If SQLancer++ does not find any bugs, it executes infinitely. The option --num-tries can be used to control after how many bugs SQLancer++ terminates. Alternatively, the option --timeout-seconds can be used to specify the maximum duration that SQLancer++ is allowed to run.

To add support for a new DBMS:

1. Add an enum in GeneralDatabaseEngineFactory inside GeneralOptions.java (e.g., MYDBMS).
2. Configure JDBC in dbconfigs/jdbc.properties: supply a URL template and default connection properties for your engine (with placeholders {host}, {port}, {user}, {password}).
3. Optional: Provide DBMS-specific environment setup or custom initialization by overriding cleanOrSetUpDatabase in the enum if your system needs more than the default database creation and table cleanup logic (see COCKROACHDB for an example).

By default, SQLancer++ will use cleanOrSetUpDatabase method to create a clean space for tables after connecting to the system by using above JDBC String. It will first try to CREATE DATABASE and USE it (like in MySQL). If it fails, it will try to blindly use DROP TABLE to clean all the possible tables.

The general workflow of SQLancer++ is as follows:

1. Connect to a database
2. Setup a new database state
3. Query the database and validate the results

1. Add a new enum value $DBMS in GeneralDatabaseEngineFactory (GeneralOptions.java) and add the corresponding entries in dbconfigs/jdbc.properties. Build with mvn package -DskipTests.
2. Start your DBMS instance.
3. Run: java -jar target/sqlancer-2.0.0.jar --use-reducer general --database-engine $DBMS
4. Check logs/general or the shell output for bugs.
   • *-cur.log: all executed statements
   • *.log: statements that triggered a potential bug (reduced if --use-reducer is enabled)

You could adjust some arguments to control the testing process. Here are some of them which might be helpful:

• --num-threads $i: the number of threads to run the test. The default value is 4. You could set it to a higher value if you have a powerful machine and there are not so many bugs. Set to 1 if there is too many issues.
• --use-reducer: enable the reducer to reduce the bug-triggering query. Do not enable it if you want to see the full SQL statements.
• --oracle $ORACLE: the oracle to use. The default value is WHERE. You could also try NoREC.
• --use-deduplicator: enable the bug deduplicator to reduce duplication in best effort. To enable it, add --use-deduplicator after general in the command.