Feature/43 implement create drop schema (#44)

* #43: implemented create schema statement
* #43: implemented drop schema statement
* #43: moved classes into appropriate packages

README.md

@@ -28,17 +28,7 @@ Goals:
 
 ## Usage
 
-```java
-import com.exasol.sql.StatementFactory;
-import com.exasol.sql.SqlStatement;
-import com.exasol.sql.rendering.SelectRenderer;
-
-SqlStatement statement = StatementFactory.getInstance()
-  .select().field("firstname", "lastname")
-  .from().table("person");
-
-String statementText = SqlStatementRenderer.render(statement);
-```
+Please read our [User Guide](../sql-statement-builder/doc/guide/user_guide.md) to find information about usage of `sql-statement-builder`.
 
 ## Development
 

doc/guide/statements/create_schema.md

@@ -0,0 +1,27 @@
+# CREATE SCHEMA
+
+The `CreateSchema` class of the SQL Statement Builder provides an entry 
+point to defining a CREATE SCHEMA SQL statement.
+
+## Usage
+
+1. Create an instance of the `CreateSchema` class through the `StatementFactory`
+
+  ```java
+  CreateSchema createSchema = StatementFactory.getInstance().createSchema("schemaName");
+  ```
+
+2. Render the instance of `CreateSchema` class. Click [here](../rendering.md) for more information on Rendering SQL Statement.
+
+- The complete example code
+
+  ```java
+  CreateSchema createSchema = StatementFactory.getInstance().createSchema("schemaName");
+
+  //optional step: add config
+  StringRendererConfig config = StringRendererConfig.builder().lowerCase(true).build();
+  CreateSchemaRenderer renderer = CreateSchemaRenderer.create(config);
+  createSchema.accept(renderer);
+
+  String renderedString = renderer.render();
+  ```

doc/guide/statements/drop_schema.md

@@ -0,0 +1,49 @@
+# DROP SCHEMA
+
+The `DropSchema` class of the SQL Statement Builder provides an entry 
+point to defining a DROP SCHEMA SQL statement.
+
+## Usage
+
+1. Create an instance of the `DropSchema` class through the `StatementFactory`
+
+   ```java
+   DropSchema dropSchema = StatementFactory.getInstance().dropSchema("schemaName");
+   ```
+
+2. Add available options using fluent programming if necessary.
+
+    The following options are currently supported:
+
+    - `IF EXISTS`
+    - `CASCADE`
+    - `RESTRICT`
+
+    Example:
+
+    ```java
+    dropSchema.ifExists().cascade();
+    ```
+    Please do not use methods `cascade()` and `restrict()` on the same object.
+    If both these options are used on the same object, `IllegalArgumentException` will be thrown.
+
+3. Render the instance of `DropSchema` class. Click [here](../rendering.md) for more information on Rendering SQL Statement.
+
+   - The complete example code
+
+    ```java
+     DropSchema dropSchema = StatementFactory.getInstance().dropSchema("schemaName");
+
+     //optional step: add additional clauses
+     dropSchema.ifExists().cascade();
+     //or
+     dropSchema.ifExists().restrict();
+
+     //Rendering
+     //optional step: add config
+     StringRendererConfig config = StringRendererConfig.builder().lowerCase(true).build();
+
+     DropSchemaRenderer renderer = DropSchemaRenderer.create(config);
+     dropSchema.accept(renderer);
+     String renderedString = renderer.render();
+     ```

doc/guide/user_guide.md

@@ -17,6 +17,8 @@ you can, for example, use the SSB to render the statement into an SQL string."
 **Currently supported SQL statements:**
 
 DDL:
+- [CREATE SCHEMA](../guide/statements/create_schema.md)
+- [DROP SCHEMA](../guide/statements/drop_schema.md)
 - [CREATE TABLE](../guide/statements/create_table.md)
 - [DROP TABLE](../guide/statements/drop_table.md)
 

doc/system_requirements.md

@@ -198,7 +198,15 @@ Needs: dsn
 #### CREATE Statements
 `req~create-statements~1`
 
-ESB supports the following create statement:
+ESB supports the following create statements.
+
+Create schema:
+
+    create-statement = "CREATE SCHEMA" schema-reference 
+
+    schema-reference = schema
+
+Create table: 
 
     create-statement = "CREATE TABLE" table-reference table-element-list
 
@@ -215,7 +223,15 @@ Needs: dsn
 #### DROP Statements
 `req~drop-statements~1`
 
-ESB supports the following drop statement:
+ESB supports the following drop statement.
+
+Drop schema:
+
+    drop-statement = "DROP SCHEMA" [IF EXISTS] schema-reference [CASCADE / RESTRICT]
+
+    schema-reference = schema
+
+Drop table:
 
     drop-statement = "DROP TABLE" [IF EXISTS] table-reference [CASCADE CONSTRAINTS]
 

pom.xml

@@ -3,7 +3,7 @@
   <modelVersion>4.0.0</modelVersion>
   <groupId>com.exasol</groupId>
   <artifactId>sql-statement-builder</artifactId>
-  <version>1.0.0</version>
+  <version>1.1.0</version>
   <name>Exasol SQL Statement Builder</name>
   <description>This module provides a Builder for SQL statements that helps creating the correct structure and validates variable parts of the statements.</description>
   <url>https://github.com/exasol/sql-statement-builder</url>

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

@@ -1,9 +1,11 @@
 package com.exasol.sql;
 
+import com.exasol.sql.ddl.create.CreateSchema;
 import com.exasol.sql.ddl.create.CreateTable;
+import com.exasol.sql.ddl.drop.DropSchema;
 import com.exasol.sql.ddl.drop.DropTable;
-import com.exasol.sql.dml.Insert;
-import com.exasol.sql.dql.Select;
+import com.exasol.sql.dml.insert.Insert;
+import com.exasol.sql.dql.select.Select;
 
 /**
  * The {@link StatementFactory} implements an factory for SQL statements.
@@ -56,6 +58,16 @@ 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(final String schemaName) {
+        return new CreateSchema(schemaName);
+    }
+
     /**
      * Create a {@link DropTable} statement
      *
@@ -65,4 +77,14 @@ public CreateTable createTable(final String tableName) {
     public DropTable dropTable(final String tableName) {
         return new DropTable(tableName);
     }
+
+    /**
+     * Create a {@link DropSchema} statement
+     *
+     * @param schemaName name of the schema to drop
+     * @return a new instance of a {@link DropSchema} statement
+     */
+    public DropSchema dropSchema(final String schemaName) {
+        return new DropSchema(schemaName);
+    }
 }

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/TableValuesVisitor.java

@@ -1,9 +1,8 @@
 package com.exasol.sql;
 
-import com.exasol.sql.dql.ValueTable;
-import com.exasol.sql.dql.ValueTableRow;
+public interface TableValuesVisitor {
+    public void visit(Table table);
 
-public interface TableValuesVisitor extends SqlStatementVisitor {
     public void visit(Field field);
 
     public void visit(ValueTable valueTable);

src/main/java/com/exasol/sql/dql/ValueTable.java → src/main/java/com/exasol/sql/ValueTable.java

@@ -1,10 +1,8 @@
-package com.exasol.sql.dql;
+package com.exasol.sql;
 
 import java.util.ArrayList;
 import java.util.List;
 
-import com.exasol.sql.*;
-
 /**
  * Value tables are pseudo-tables constructed from rows and columns of expressions (e.g. literals)
  *

src/main/java/com/exasol/sql/dql/ValueTableRow.java → src/main/java/com/exasol/sql/ValueTableRow.java

@@ -1,10 +1,9 @@
-package com.exasol.sql.dql;
+package com.exasol.sql;
 
-import java.util.*;
-
-import com.exasol.sql.*;
 import com.exasol.sql.expression.*;
 
+import java.util.*;
+
 /**
  * This class represents a row in a {@link ValueTable}.
  */
@@ -15,8 +14,7 @@ public class ValueTableRow extends AbstractFragment {
     /**
      * Create a value table row from a list of expressions
      *
-     * @param root root node of the SQL statement
-     *
+     * @param root        root node of the SQL statement
      * @param expressions value expressions
      */
     public ValueTableRow(final Fragment root, final ValueExpression... expressions) {
@@ -27,8 +25,7 @@ public ValueTableRow(final Fragment root, final ValueExpression... expressions)
     /**
      * Create a value table row from a list of string literals
      *
-     * @param root root node of the SQL statement
-     *
+     * @param root   root node of the SQL statement
      * @param values sting literals
      */
     public ValueTableRow(final Fragment root, final String... values) {
@@ -84,7 +81,6 @@ public Builder(final Fragment root) {
          * Add one or more string literals to the row
          *
          * @param values strings to be added
-         *
          * @return <code>this</code> for fluent programming
          */
         public Builder add(final String... values) {
@@ -98,7 +94,6 @@ public Builder add(final String... values) {
          * Add one or more integer literals to the row
          *
          * @param values integers to be added
-         *
          * @return <code>this</code> for fluent programming
          */
         public Builder add(final int... values) {
@@ -122,7 +117,6 @@ public Builder addPlaceholder() {
          * Add a list of expressions to the {@link ValueTableRow}
          *
          * @param expressions expressions to be added
-         *
          * @return <code>this</code> for fluent programming
          */
         public Builder add(final List<ValueExpression> expressions) {

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

@@ -0,0 +1,41 @@
+package com.exasol.sql.ddl;
+
+import com.exasol.sql.AbstractFragment;
+import com.exasol.sql.Fragment;
+import com.exasol.sql.ddl.create.CreateSchemaVisitor;
+import com.exasol.sql.ddl.drop.DropSchemaVisitor;
+
+/**
+ * This class represents a {@link Schema} in an SQL Statement
+ */
+public class Schema extends AbstractFragment {
+    private final String name;
+
+    /**
+     * Create a new {@link Schema}
+     *
+     * @param root       SQL statement this schema belongs to
+     * @param schemaName schema name
+     */
+    public Schema(final Fragment root, final String schemaName) {
+        super(root);
+        this.name = schemaName;
+    }
+
+    /**
+     * Get the schema name
+     *
+     * @return schema name
+     */
+    public String getName() {
+        return name;
+    }
+
+    public void accept(final CreateSchemaVisitor visitor) {
+        visitor.visit(this);
+    }
+
+    public void accept(final DropSchemaVisitor visitor) {
+        visitor.visit(this);
+    }
+}