Implement a simple sql template to support Postgre

Signed-off-by: Paolo Di Tommaso <[email protected]>

src/main/java/io/seqera/migtool/App.java

@@ -2,6 +2,7 @@
 
 import java.util.concurrent.Callable;
 
+import io.seqera.migtool.builder.SqlTemplate;
 import picocli.CommandLine;
 import picocli.CommandLine.Command;
 import picocli.CommandLine.Option;
@@ -51,7 +52,8 @@ public Integer call() {
                 .withDialect(dialect!=null ? dialect : dialectFromUrl(url))
                 .withDriver(driver!=null ? driver : driverFromUrl(url))
                 .withLocations(location)
-                .withPattern(pattern);
+                .withPattern(pattern)
+                .withBuilder(SqlTemplate.from(dialect!=null ? dialect : dialectFromUrl(url)));
 
         try {
             tool.run();

src/main/java/io/seqera/migtool/Helper.java

@@ -216,6 +216,8 @@ static public String driverFromUrl(String url) {
             return "org.h2.Driver";
         if( "sqlite".equals(dialect))
             return "org.sqlite.JDBC";
+        if( "postgresql".equals(dialect))
+            return "org.postgresql.Driver";
         return null;
     }
 }

src/main/java/io/seqera/migtool/MigTool.java

@@ -21,6 +21,8 @@
 import groovy.lang.Closure;
 import groovy.lang.GroovyShell;
 import groovy.sql.Sql;
+import io.seqera.migtool.builder.DefaultSqlTemplate;
+import io.seqera.migtool.builder.SqlTemplate;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -42,7 +44,7 @@ public class MigTool {
 
     static final String MIGTOOL_TABLE = "MIGTOOL_HISTORY";
 
-    static final String[] DIALECTS = {"h2", "mysql", "mariadb","sqlite"};
+    static final String[] DIALECTS = {"h2", "mysql", "mariadb","sqlite","postgresql"};
 
     String driver;
     String url;
@@ -54,6 +56,7 @@ public class MigTool {
     Pattern pattern;
     String schema;
     String catalog;
+    SqlTemplate builder = new DefaultSqlTemplate();
 
     private final List<MigRecord> migrationEntries;
     private final List<MigRecord> patchEntries;
@@ -106,6 +109,11 @@ public MigTool withPattern(String pattern) {
         return this;
     }
 
+    public MigTool withBuilder(SqlTemplate builder) {
+        this.builder = builder;
+        return this;
+    }
+
     /**
      * Main application entry point
      */
@@ -350,7 +358,7 @@ protected void apply() {
 
     protected void checkRank(MigRecord entry) {
         try(Connection conn=getConnection(); Statement stm = conn.createStatement()) {
-            ResultSet rs = stm.executeQuery("select max(`rank`) from "+MIGTOOL_TABLE);
+            ResultSet rs = stm.executeQuery(builder.selectMaxRank(MIGTOOL_TABLE));
             int last = rs.next() ? rs.getInt(1) : 0;
             int expected = last+1;
             if( entry.rank != expected) {
@@ -434,7 +442,7 @@ private int migrate(MigRecord entry) throws SQLException {
         int delta = (int)(System.currentTimeMillis()-now);
 
         // save the current migration
-        final String insertSql = "insert into "+MIGTOOL_TABLE+" (`rank`,`script`,`checksum`,`created_on`,`execution_time`) values (?,?,?,?,?)";
+        final String insertSql = builder.insetMigration(MIGTOOL_TABLE);
         try (Connection conn=getConnection(); PreparedStatement insert = conn.prepareStatement(insertSql)) {
             insert.setInt(1, entry.rank);
             insert.setString(2, entry.script);
@@ -447,7 +455,7 @@ private int migrate(MigRecord entry) throws SQLException {
     }
 
     protected boolean checkMigrated(MigRecord entry) {
-        String sql = "select `id`, `checksum`, `script` from " + MIGTOOL_TABLE + " where `rank` = ? and `script` = ?";
+        final String sql = builder.selectMigration(MIGTOOL_TABLE);
 
         try (Connection conn=getConnection(); PreparedStatement stm = conn.prepareStatement(sql)) {
             stm.setInt(1, entry.rank);

src/main/java/io/seqera/migtool/builder/DefaultSqlTemplate.java

@@ -0,0 +1,22 @@
+package io.seqera.migtool.builder;
+
+/**
+ *
+ * @author Paolo Di Tommaso <[email protected]>
+ */
+public class DefaultSqlTemplate extends SqlTemplate {
+    @Override
+    public String selectMaxRank(String table) {
+        return "select max(`rank`) from " + table;
+    }
+
+    @Override
+    public String insetMigration(String table) {
+        return "insert into "+table+" (`rank`,`script`,`checksum`,`created_on`,`execution_time`) values (?,?,?,?,?)";
+    }
+
+    @Override
+    public String selectMigration(String table) {
+        return "select `id`, `checksum`, `script` from "+table+ " where `rank` = ? and `script` = ?";
+    }
+}

src/main/java/io/seqera/migtool/builder/PostgresSqlTemplate.java

@@ -0,0 +1,24 @@
+package io.seqera.migtool.builder;
+
+/**
+ *
+ * @author Paolo Di Tommaso <[email protected]>
+ */
+class PostgresSqlTemplate extends SqlTemplate {
+
+    @Override
+    public String selectMaxRank(String table) {
+        return "select max(rank) from " + table;
+    }
+
+    @Override
+    public String insetMigration(String table) {
+        return "insert into "+table+" (rank,script,checksum,created_on,execution_time) values (?,?,?,?,?)";
+    }
+
+    @Override
+    public String selectMigration(String table) {
+        return "select id, checksum, script from "+table+ " where rank = ? and script = ?";
+    }
+
+}

src/main/java/io/seqera/migtool/builder/SqlTemplate.java

@@ -0,0 +1,22 @@
+package io.seqera.migtool.builder;
+
+/**
+ *
+ * @author Paolo Di Tommaso <[email protected]>
+ */
+public abstract class SqlTemplate {
+
+    abstract public String selectMaxRank(String table);
+
+    abstract public String insetMigration(String table);
+
+    abstract public String selectMigration(String table);
+
+    static public SqlTemplate from(String dialect) {
+        if( "postgresql".equals(dialect) )
+            return new PostgresSqlTemplate();
+        else
+            return new DefaultSqlTemplate();
+    }
+
+}