SQLSchemaSynchronizer now orders columns to prevent unexpected column actions

Author: ZorTik

api/src/main/java/me/zort/sqllib/api/model/TableSchema.java

@@ -14,6 +14,13 @@ public ColumnDefinition getDefinitionDetails(int index) {
         return definitions[index];
     }
 
+    public ColumnDefinition getDefinitionDetails(String name) {
+        for (ColumnDefinition definition : definitions) {
+            if (definition.getName().equals(name)) return definition;
+        }
+        return null;
+    }
+
     public String getDefinitionName(int index) {
         return getDefinitionDetails(index).getName();
     }

core/src/main/java/me/zort/sqllib/model/schema/SQLSchemaSynchronizer.java

@@ -26,9 +26,10 @@ public class SQLSchemaSynchronizer implements SchemaSynchronizer<SQLDatabaseConn
     @Override
     public QueryResult synchronize(SQLDatabaseConnection source, TableSchema from, TableSchema to) {
         List<String> columnQueries = new ArrayList<>();
-        for (int i = 0; i < Math.max(from.size(), to.size()); i++) {
-            ColumnDefinition fromDefinition = from.size() > i ? from.getDefinitionDetails(i) : null;
-            ColumnDefinition toDefinition = to.size() > i ? to.getDefinitionDetails(i) : null;
+        ColumnDefinition[][] definitions = orderDefinitions(from, to);
+        for (int i = 0; i < Math.max(definitions[0].length, definitions[1].length); i++) {
+            final ColumnDefinition fromDefinition = definitions[0][i];
+            final ColumnDefinition toDefinition = definitions[1][i];
 
             if (fromDefinition == null && toDefinition != null) {
                 columnQueries.addAll(columnQueryBuilder.buildActionQuery(SQLColumnQueryBuilder.ColumnAction.DROP, from.getTable(), fromDefinition, toDefinition));
@@ -55,4 +56,25 @@ public QueryResult synchronize(SQLDatabaseConnection source, TableSchema from, T
         }
         return results.stream().allMatch(QueryResult::isSuccessful) ? QueryResult.successful() : new QueryResultImpl(false);
     }
+
+    private static ColumnDefinition[][] orderDefinitions(TableSchema one, TableSchema two) {
+        int maxSize = Math.max(one.size(), two.size());
+        ColumnDefinition[][] definitions = new ColumnDefinition[2][maxSize];
+        for (int i = 0; i < maxSize; i++) {
+            if (one.size() > i && two.size() > i && two.getDefinitionDetails(one.getDefinitionName(i)) != null) {
+                definitions[0][i] = one.getDefinitionDetails(i);
+                definitions[1][i] = two.getDefinitionDetails(one.getDefinitionName(i));
+            } else if (one.size() > i && two.size() > i) {
+                definitions[0][i] = one.getDefinitionDetails(i);
+                definitions[1][i] = two.getDefinitionDetails(i);
+            } else if (one.size() > i) {
+                definitions[0][i] = one.getDefinitionDetails(i);
+                definitions[1][i] = null;
+            } else if (two.size() > i) {
+                definitions[1][i] = two.getDefinitionDetails(i);
+                definitions[0][i] = null;
+            }
+        }
+        return definitions;
+    }
 }