Initial Data Model for Schema SQL Generation

spring-data-relational/src/main/java/org/springframework/data/relational/core/mapping/schemasqlgeneration/SchemaSQLGenerator.java

@@ -0,0 +1,113 @@
+/*
+ * Copyright 2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.relational.core.mapping.schemasqlgeneration;
+
+import org.springframework.data.relational.core.sql.IdentifierProcessing;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+
+public class SchemaSQLGenerator {
+
+    private final IdentifierProcessing identifierProcssing;
+    public SchemaSQLGenerator(IdentifierProcessing identifierProcessing) {
+        this.identifierProcssing = identifierProcessing;
+    }
+
+    List<List<TableModel>> reorderTablesInHierarchy(SchemaSQLGenerationDataModel dataModel) {
+
+        // ::TODO:: Take Parent/Child relationships into account (i.e if a child table has
+        // a Foreign Key to a table, that parent table needs to be created first.
+
+        // For now this method will simple put the tables in the same level
+        List<List<TableModel>> orderedTables = new ArrayList<List<TableModel>>();
+        List<TableModel> tables = new ArrayList<TableModel>();
+
+        for (TableModel table : dataModel.getTableData()) {
+            tables.add(table);
+        }
+        orderedTables.add(tables);
+
+        return orderedTables;
+    }
+
+    HashMap<Class<?>,String> mapClassToSQLType = null;
+
+    public String generateSQL(ColumnModel column) {
+
+        StringBuilder sql = new StringBuilder();
+        sql.append(column.getName().toSql(identifierProcssing));
+        sql.append(" ");
+
+        sql.append(column.getType());
+
+        if (!column.isNullable()) {
+            sql.append(" NOT NULL");
+        }
+
+        return sql.toString();
+    }
+
+    public String generatePrimaryKeySQL(TableModel table) {
+        // ::TODO:: Implement
+        return "";
+    }
+
+    public String generateForeignKeySQL(TableModel table) {
+        // ::TODO:: Implement
+        return "";
+    }
+
+    public String generateSQL(TableModel table) {
+
+        StringBuilder sql = new StringBuilder();
+
+        sql.append("CREATE TABLE ");
+        sql.append(table.getName().toSql(identifierProcssing));
+        sql.append(" (");
+
+        int numColumns = table.getColumns().size();
+        for (int i=0; i < numColumns; i++) {
+            sql.append(generateSQL(table.getColumns().get(i)));
+            if (i != numColumns-1) {
+                sql.append(",");
+            }
+        }
+
+        sql.append(generatePrimaryKeySQL(table));
+        sql.append(generateForeignKeySQL(table));
+
+        sql.append(" );");
+
+        return sql.toString();
+    }
+
+    public String generateSQL(SchemaSQLGenerationDataModel dataModel) {
+
+        StringBuilder sql = new StringBuilder();
+        List<List<TableModel>> orderedTables = reorderTablesInHierarchy(dataModel);
+
+        for (List<TableModel> tables : orderedTables) {
+            for (TableModel table : tables) {
+                String tableSQL = generateSQL(table);
+                sql.append(tableSQL + "\n");
+            }
+        }
+
+        return sql.toString();
+    }
+}

spring-data-relational/src/test/java/org/springframework/data/relational/schemasqlgeneration/SchemaSQLGenerationDataModelTests.java

@@ -22,6 +22,8 @@
 import org.springframework.data.relational.core.mapping.schemasqlgeneration.SchemaSQLGenerationDataModel;
 import org.springframework.data.relational.core.mapping.schemasqlgeneration.SchemaSQLGenerator;
 import org.springframework.data.relational.core.mapping.schemasqlgeneration.TableModel;
+import org.springframework.data.relational.core.sql.IdentifierProcessing;
+import org.springframework.util.StringUtils;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -33,28 +35,28 @@
 public class SchemaSQLGenerationDataModelTests {
 
     @Test
-    void testBasicModelGeneration() {
+    void testBasicSchemaSQLGeneration() {
+
+        IdentifierProcessing.Quoting quoting = new IdentifierProcessing.Quoting("`");
+        IdentifierProcessing identifierProcessing = IdentifierProcessing.create(quoting, IdentifierProcessing.LetterCasing.LOWER_CASE);
+        SchemaSQLGenerator generator = new SchemaSQLGenerator(identifierProcessing);
+
         RelationalMappingContext context = new RelationalMappingContext();
         context.getRequiredPersistentEntity(SchemaSQLGenerationDataModelTests.Luke.class);
-        context.getRequiredPersistentEntity(SchemaSQLGenerationDataModelTests.Vader.class);
 
         SchemaSQLGenerationDataModel model = new SchemaSQLGenerationDataModel(context);
+        String sql = generator.generateSQL(model);
+        assertThat(sql).isEqualTo("CREATE TABLE `luke` (`force` VARCHAR(255),`be` VARCHAR(255),`with` VARCHAR(255),`you` VARCHAR(255) );\n");
 
-        assertThat(model.getTableData().size()).isEqualTo(2);
-
-        TableModel t1 = model.getTableData().get(1);
-        assertThat(t1.getName().getReference()).isEqualTo("luke");
-        assertThat(t1.getColumns().get(0).getName()).isEqualTo("force");
-        assertThat(t1.getColumns().get(1).getName()).isEqualTo("be");
-        assertThat(t1.getColumns().get(2).getName()).isEqualTo("with");
-        assertThat(t1.getColumns().get(3).getName()).isEqualTo("you");
+        context = new RelationalMappingContext();
+        context.getRequiredPersistentEntity(SchemaSQLGenerationDataModelTests.Vader.class);
 
-        TableModel t2 = model.getTableData().get(1);
-        assertThat(t2.getName()).isEqualTo("vader");
-        assertThat(t2.getColumns().get(0).getName()).isEqualTo("luke_i_am_your_father");
-        assertThat(t2.getColumns().get(1).getName()).isEqualTo("dark_side");
+        model = new SchemaSQLGenerationDataModel(context);
+        sql = generator.generateSQL(model);
+        assertThat(sql).isEqualTo("CREATE TABLE `vader` (`luke_i_am_your_father` VARCHAR(255),`dark_side` TINYINT,`floater` FLOAT,`double_class` DOUBLE,`integer_class` INT );\n");
     }
 
+
     @Table
     static class Luke {
         @Column
@@ -73,6 +75,12 @@ static class Vader {
         public String lukeIAmYourFather;
         @Column
         public Boolean darkSide;
+        @Column
+        public Float floater;
+        @Column
+        public Double doubleClass;
+        @Column
+        public Integer integerClass;
     }