working on hamonization of db implementations

Signed-off-by: Stephan Richter <s.richter@srsoftware.de>

core/src/main/java/de/srsoftware/umbrella/core/BaseDb.java

@@ -0,0 +1,64 @@
+package de.srsoftware.umbrella.core;
+
+import de.srsoftware.tools.jdbc.Query;
+
+import java.sql.Connection;
+import java.sql.SQLException;
+
+import static de.srsoftware.tools.jdbc.Condition.equal;
+import static de.srsoftware.tools.jdbc.Query.replaceInto;
+import static de.srsoftware.umbrella.core.Constants.*;
+import static de.srsoftware.umbrella.core.Constants.TABLE_SETTINGS;
+import static java.lang.System.Logger.Level.ERROR;
+import static java.lang.System.Logger.Level.INFO;
+import static java.text.MessageFormat.format;
+
+public abstract class BaseDb {
+	private final System.Logger LOG = System.getLogger(getClass().getSimpleName());
+
+	protected final Connection db;
+
+	public BaseDb(Connection connection) {
+		db = connection;
+		var version = createTables();
+		LOG.log(INFO,"Updated db to version {0}",version);
+
+	}
+
+	protected abstract int createTables();
+
+	protected int createSettingsTable() {
+		var createTable = """
+CREATE TABLE IF NOT EXISTS {0} ( {1} VARCHAR(255) PRIMARY KEY, {2} VARCHAR(255) NOT NULL);
+""";
+		try {
+			var stmt = db.prepareStatement(format(createTable,TABLE_SETTINGS, KEY, VALUE));
+			stmt.execute();
+			stmt.close();
+		} catch (SQLException e) {
+			LOG.log(ERROR,ERROR_FAILED_CREATE_TABLE,TABLE_SETTINGS,e);
+			throw new RuntimeException(e);
+		}
+
+		var version = 0;
+		try {
+			var rs = Query.select(VALUE).from(TABLE_SETTINGS).where(KEY, equal(DB_VERSION)).exec(db);
+			if (rs.next()) version = rs.getInt(VALUE);
+			rs.close();
+
+			return version;
+		} catch (SQLException e) {
+			LOG.log(ERROR,ERROR_READ_TABLE,DB_VERSION,TABLE_SETTINGS,e);
+			throw new RuntimeException(e);
+		}
+	}
+
+	protected int setCurrentVersion(int version)  {
+		try {
+			replaceInto(TABLE_SETTINGS, KEY, VALUE).values(DB_VERSION,version).execute(db).close();
+		} catch (SQLException e) {
+			throw new RuntimeException(e);
+		}
+		return version;
+	}
+}

core/src/main/java/de/srsoftware/umbrella/core/Constants.java

@@ -23,6 +23,7 @@ public class Constants {
 	public static final String CUSTOMER_NUMBER_PREFIX = "customer_number_prefix";
 
 	public static final String DATA = "data";
+	public static final String DB_VERSION = "db_version";
 	public static final String DATE = "date";
 	public static final String DECIMALS = "decimals";
 	public static final String DECIMAL_SEPARATOR = "decimal_separator";