CreateViewChange.java

package liquibase.change.core;

import liquibase.change.AbstractChange;
import liquibase.change.Change;
import liquibase.change.ChangeMetaData;
import liquibase.database.Database;
import liquibase.database.core.MSSQLDatabase;
import liquibase.database.core.SQLiteDatabase;
import liquibase.statement.SqlStatement;
import liquibase.statement.core.CreateViewStatement;
import liquibase.statement.core.DropViewStatement;
import liquibase.util.StringUtils;

import java.util.ArrayList;
import java.util.List;

/**
 * Creates a new view.
 */
public class CreateViewChange extends AbstractChange {

	private String schemaName;
	private String viewName;
	private String selectQuery;
	private Boolean replaceIfExists;

	public CreateViewChange() {
		super("createView", "Create View", ChangeMetaData.PRIORITY_DEFAULT);
	}

	public String getSchemaName() {
		return schemaName;
	}

	public void setSchemaName(String schemaName) {
		this.schemaName = StringUtils.trimToNull(schemaName);
	}

	public String getViewName() {
		return viewName;
	}

	public void setViewName(String viewName) {
		this.viewName = viewName;
	}

	public String getSelectQuery() {
		return selectQuery;
	}

	public void setSelectQuery(String selectQuery) {
		this.selectQuery = selectQuery;
	}

	public Boolean getReplaceIfExists() {
		return replaceIfExists;
	}

	public void setReplaceIfExists(Boolean replaceIfExists) {
		this.replaceIfExists = replaceIfExists;
	}

	public SqlStatement[] generateStatements(Database database) {
		List<SqlStatement> statements = new ArrayList<SqlStatement>();

		boolean replaceIfExists = false;
		if (getReplaceIfExists() != null && getReplaceIfExists()) {
			replaceIfExists = true;
		}

		if (!supportsReplaceIfExistsOption(database) && replaceIfExists) {
			statements.add(new DropViewStatement(
					getSchemaName() == null ? database.getDefaultSchemaName()
							: getSchemaName(), getViewName()));
			statements.add(new CreateViewStatement(
					getSchemaName() == null ? database.getDefaultSchemaName()
							: getSchemaName(), getViewName(), getSelectQuery(),
					false));
		} else {
			statements.add(new CreateViewStatement(
					getSchemaName() == null ? database.getDefaultSchemaName()
							: getSchemaName(), getViewName(), getSelectQuery(),
					replaceIfExists));
		}

		return statements.toArray(new SqlStatement[statements.size()]);
	}

	public String getConfirmationMessage() {
		return "View " + getViewName() + " created";
	}

	@Override
	protected Change[] createInverses() {
		DropViewChange inverse = new DropViewChange();
		inverse.setViewName(getViewName());
		inverse.setSchemaName(getSchemaName());

		return new Change[] { inverse };
	}

	private boolean supportsReplaceIfExistsOption(Database database) {
		return !(database instanceof SQLiteDatabase
		    || database instanceof MSSQLDatabase);
	}

}