#43: implemented create schema logic

src/main/java/com/exasol/sql/StatementFactory.java

@@ -1,5 +1,6 @@
 package com.exasol.sql;
 
+import com.exasol.sql.ddl.create.CreateSchema;
 import com.exasol.sql.ddl.create.CreateTable;
 import com.exasol.sql.ddl.drop.DropTable;
 import com.exasol.sql.dml.Insert;
@@ -56,6 +57,16 @@ public CreateTable createTable(final String tableName) {
         return new CreateTable(tableName);
     }
 
+    /**
+     * Create a {@link CreateSchema} statement
+     *
+     * @param schemaName name of the schema to create
+     * @return a new instance of a {@link CreateSchema} statement
+     */
+    public CreateSchema createSchema(String schemaName) {
+        return new CreateSchema(schemaName);
+    }
+
     /**
      * Create a {@link DropTable} statement
      *

src/main/java/com/exasol/sql/Table.java

@@ -1,5 +1,8 @@
 package com.exasol.sql;
 
+import com.exasol.sql.ddl.create.CreateTableVisitor;
+import com.exasol.sql.ddl.drop.DropTableVisitor;
+
 import java.util.Optional;
 
 /**
@@ -26,7 +29,7 @@ public Table(final Fragment root, final String name) {
      *
      * @param root SQL statement this table belongs to
      * @param name table name
-     * @param as table alias
+     * @param as   table alias
      */
     public Table(final Fragment root, final String name, final String as) {
         super(root);
@@ -52,7 +55,15 @@ public Optional<String> getAs() {
         return this.as;
     }
 
-    public void accept(final SqlStatementVisitor visitor) {
+    public void accept(final TableValuesVisitor visitor) {
+        visitor.visit(this);
+    }
+
+    public void accept(final CreateTableVisitor visitor) {
+        visitor.visit(this);
+    }
+
+    public void accept(final DropTableVisitor visitor) {
         visitor.visit(this);
     }
 }

src/main/java/com/exasol/sql/ddl/Schema.java

@@ -0,0 +1,36 @@
+package com.exasol.sql.ddl;
+
+import com.exasol.sql.AbstractFragment;
+import com.exasol.sql.Fragment;
+import com.exasol.sql.ddl.create.CreateSchemaVisitor;
+
+/**
+ * This class represents a {@link Schema} in an SQL Statement
+ */
+public class Schema extends AbstractFragment {
+    private String name;
+
+    /**
+     * Create a new {@link Schema}
+     *
+     * @param root       SQL statement this schema belongs to
+     * @param schemaName schema name
+     */
+    public Schema(Fragment root, String schemaName) {
+        super(root);
+        this.name = schemaName;
+    }
+
+    /**
+     * Get a schema name
+     *
+     * @return schema name
+     */
+    public String getName() {
+        return name;
+    }
+
+    public void accept(CreateSchemaVisitor visitor) {
+        visitor.visit(this);
+    }
+}

src/main/java/com/exasol/sql/ddl/create/CreateSchema.java

@@ -0,0 +1,37 @@
+package com.exasol.sql.ddl.create;
+
+import com.exasol.sql.AbstractFragment;
+import com.exasol.sql.SqlStatement;
+import com.exasol.sql.ddl.Schema;
+
+/**
+ * This class implements an SQL {@link CreateSchema} statement
+ */
+public class CreateSchema extends AbstractFragment implements SqlStatement, CreateSchemaFragment {
+    private Schema schema;
+
+    /**
+     * Create a new instance of an {@link CreateSchema} statement
+     *
+     * @param schemaName name of the table to create
+     */
+    public CreateSchema(final String schemaName) {
+        super(null);
+        this.schema = new Schema(this, schemaName);
+    }
+
+    /**
+     * Get a schema name
+     *
+     * @return schema name
+     */
+    public String getSchemaName() {
+        return schema.getName();
+    }
+
+    @Override
+    public void accept(CreateSchemaVisitor visitor) {
+        visitor.visit(this);
+        this.schema.accept(visitor);
+    }
+}

src/main/java/com/exasol/sql/ddl/create/CreateSchemaFragment.java

@@ -0,0 +1,15 @@
+package com.exasol.sql.ddl.create;
+
+import com.exasol.sql.Fragment;
+
+/**
+ * This is the common interface for all fragments of a CREATE SCHEMA statement.
+ */
+public interface CreateSchemaFragment extends Fragment {
+    /**
+     * Accept a visitor (e.g. a renderer or validator)
+     *
+     * @param visitor visitor to accept
+     */
+    public void accept(CreateSchemaVisitor visitor);
+}

src/main/java/com/exasol/sql/ddl/create/CreateSchemaVisitor.java

@@ -0,0 +1,9 @@
+package com.exasol.sql.ddl.create;
+
+import com.exasol.sql.ddl.Schema;
+
+public interface CreateSchemaVisitor {
+    public void visit(CreateSchema createSchema);
+
+    public void visit(Schema schema);
+}

src/main/java/com/exasol/sql/ddl/create/CreateTable.java

@@ -2,9 +2,7 @@
 
 import com.exasol.datatype.type.Boolean;
 import com.exasol.datatype.type.*;
-import com.exasol.sql.AbstractFragment;
-import com.exasol.sql.SqlStatement;
-import com.exasol.sql.Table;
+import com.exasol.sql.*;
 
 /**
  * This class implements an SQL {@link CreateTable} statement
@@ -151,11 +149,21 @@ public synchronized CreateTable intervalYearToMonthColumn(final String columnNam
         return this;
     }
 
-    protected String getTableName() {
+    /**
+     * Get a table name
+     *
+     * @return table name
+     */
+    public String getTableName() {
         return this.table.getName();
     }
 
-    protected ColumnsDefinition getColumns() {
+    /**
+     * Get columns of a table
+     *
+     * @return columns
+     */
+    public ColumnsDefinition getColumns() {
         return this.columnsDefinition;
     }
 

src/main/java/com/exasol/sql/ddl/create/CreateTableVisitor.java

@@ -2,9 +2,11 @@
 
 import com.exasol.datatype.type.Boolean;
 import com.exasol.datatype.type.*;
-import com.exasol.sql.SqlStatementVisitor;
+import com.exasol.sql.Table;
+
+public interface CreateTableVisitor {
+    public void visit(final Table table);
 
-public interface CreateTableVisitor extends SqlStatementVisitor {
     public void visit(final CreateTable createTable);
 
     public void visit(final Column column);

src/main/java/com/exasol/sql/ddl/create/rendering/CreateSchemaRenderer.java

@@ -0,0 +1,52 @@
+package com.exasol.sql.ddl.create.rendering;
+
+import com.exasol.sql.ddl.Schema;
+import com.exasol.sql.ddl.create.CreateSchema;
+import com.exasol.sql.ddl.create.CreateSchemaVisitor;
+import com.exasol.sql.rendering.AbstractFragmentRenderer;
+import com.exasol.sql.rendering.StringRendererConfig;
+
+/**
+ * The {@link CreateSchemaRenderer} turns SQL statement structures in to SQL strings.
+ */
+public class CreateSchemaRenderer extends AbstractFragmentRenderer implements CreateSchemaVisitor {
+    /**
+     * Create a new {@link CreateSchemaRenderer} with custom render settings.
+     *
+     * @param config render configuration settings
+     */
+    public CreateSchemaRenderer(final StringRendererConfig config) {
+        super(config);
+    }
+
+    /**
+     * Create an {@link CreateSchemaRenderer} using the default renderer configuration
+     *
+     * @return insert renderer
+     */
+    public static CreateSchemaRenderer create() {
+        return new CreateSchemaRenderer(StringRendererConfig.createDefault());
+    }
+
+    /**
+     * Create an {@link CreateSchemaRenderer}
+     *
+     * @param config renderer configuration
+     * @return create schema renderer
+     */
+    public static CreateSchemaRenderer create(final StringRendererConfig config) {
+        return new CreateSchemaRenderer(config);
+    }
+
+    @Override
+    public void visit(CreateSchema createSchema) {
+        appendKeyWord("CREATE SCHEMA ");
+        setLastVisited(createSchema);
+    }
+
+    @Override
+    public void visit(Schema schema) {
+        appendAutoQuoted(schema.getName());
+        setLastVisited(schema);
+    }
+}

src/main/java/com/exasol/sql/ddl/drop/DropTableVisitor.java

@@ -1,8 +1,10 @@
 package com.exasol.sql.ddl.drop;
 
-import com.exasol.sql.SqlStatementVisitor;
+import com.exasol.sql.Table;
+
+public interface DropTableVisitor {
+    public void visit(Table table);
 
-public interface DropTableVisitor extends SqlStatementVisitor {
     public void visit(DropTable dropTable);
 
     public void visit(CascadeConstraints cascadeConstraints);

src/test/java/com/exasol/hamcrest/SqlFragmentRenderResultMatcher.java

@@ -1,6 +1,7 @@
 package com.exasol.hamcrest;
 
-import com.exasol.sql.ddl.create.CreateTableFragment;
+import com.exasol.sql.ddl.create.*;
+import com.exasol.sql.ddl.create.rendering.CreateSchemaRenderer;
 import com.exasol.sql.ddl.create.rendering.CreateTableRenderer;
 import com.exasol.sql.ddl.drop.DropTableFragment;
 import com.exasol.sql.ddl.drop.rendering.DropTableRenderer;
@@ -54,6 +55,10 @@ public boolean matchesSafely(final Fragment fragment) {
             final DropTableRenderer renderer = new DropTableRenderer(this.config);
             ((DropTableFragment) root).accept(renderer);
             this.renderedText = renderer.render();
+        } else if (root instanceof CreateSchemaFragment) {
+            final CreateSchemaRenderer renderer = new CreateSchemaRenderer(this.config);
+            ((CreateSchemaFragment) root).accept(renderer);
+            this.renderedText = renderer.render();
         } else {
             throw new UnsupportedOperationException(
                     "Don't know how to render fragment of type\"" + root.getClass().getName() + "\".");

src/test/java/com/exasol/sql/ddl/create/TestCreateSchema.java

@@ -0,0 +1,23 @@
+package com.exasol.sql.ddl.create;
+
+import com.exasol.sql.StatementFactory;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.equalTo;
+
+class TestCreateSchema {
+    private static final String TEST_SCHEMA_NAME = "test schema name";
+    private CreateSchema createSchema;
+
+    @BeforeEach
+    void setUp() {
+        createSchema = StatementFactory.getInstance().createSchema(TEST_SCHEMA_NAME);
+    }
+
+    @Test
+    void getTableName() {
+        assertThat(this.createSchema.getSchemaName(), equalTo(TEST_SCHEMA_NAME));
+    }
+}

src/test/java/com/exasol/sql/ddl/create/rendering/TestCreateSchemaRenderer.java

@@ -0,0 +1,26 @@
+package com.exasol.sql.ddl.create.rendering;
+
+import com.exasol.sql.StatementFactory;
+import com.exasol.sql.ddl.create.CreateSchema;
+import com.exasol.sql.rendering.StringRendererConfig;
+import org.junit.jupiter.api.Test;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.instanceOf;
+import static org.hamcrest.Matchers.startsWith;
+
+class TestCreateSchemaRenderer {
+    @Test
+    void testCreateWithDefaultConfig() {
+        assertThat(CreateSchemaRenderer.create(), instanceOf(CreateSchemaRenderer.class));
+    }
+
+    @Test
+    void testCreateWithConfig() {
+        final StringRendererConfig config = StringRendererConfig.builder().lowerCase(true).build();
+        final CreateSchemaRenderer renderer = CreateSchemaRenderer.create(config);
+        final CreateSchema createSchema = StatementFactory.getInstance().createSchema("test name");
+        createSchema.accept(renderer);
+        assertThat(renderer.render(), startsWith("create schema"));
+    }
+}

src/test/java/com/exasol/sql/ddl/create/rendering/TestCreateSchemaRendering.java

@@ -0,0 +1,25 @@
+package com.exasol.sql.ddl.create.rendering;
+
+import com.exasol.sql.StatementFactory;
+import com.exasol.sql.ddl.create.CreateSchema;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import static com.exasol.hamcrest.SqlFragmentRenderResultMatcher.rendersTo;
+import static org.hamcrest.MatcherAssert.assertThat;
+
+class TestCreateSchemaRendering {
+    private static final String SCHEMA_NAME = "testName";
+    private CreateSchema createSchema;
+
+    @BeforeEach
+    void beforeEach() {
+        this.createSchema = StatementFactory.getInstance().createSchema(SCHEMA_NAME);
+    }
+
+
+    @Test
+    void testCreateSchema() {
+        assertThat(this.createSchema, rendersTo("CREATE SCHEMA testName"));
+    }
+}

src/test/java/com/exasol/sql/ddl/create/rendering/TestCreateTableRenderer.java

@@ -21,6 +21,6 @@ void testCreateWithConfig() {
         final CreateTableRenderer renderer = CreateTableRenderer.create(config);
         final CreateTable createTable = StatementFactory.getInstance().createTable("test name");
         createTable.accept(renderer);
-        assertThat(renderer.render(), startsWith("create"));
+        assertThat(renderer.render(), startsWith("create table"));
     }
 }