AddNotNullConstraintChange.java

package liquibase.change.core;

import liquibase.change.AbstractChange;
import liquibase.change.Change;
import liquibase.change.ChangeMetaData;
import liquibase.change.ColumnConfig;
import liquibase.database.Database;
import liquibase.database.core.DB2Database;
import liquibase.database.core.SQLiteDatabase;
import liquibase.database.core.SQLiteDatabase.AlterTableVisitor;
import liquibase.database.structure.Index;
import liquibase.database.structure.type.BooleanType;
import liquibase.database.typeconversion.TypeConverterFactory;
import liquibase.statement.SqlStatement;
import liquibase.statement.core.ReorganizeTableStatement;
import liquibase.statement.core.SetNullableStatement;
import liquibase.statement.core.UpdateStatement;
import liquibase.util.StringUtils;

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

/**
 * Adds a not-null constraint to an existing column.
 */
public class AddNotNullConstraintChange extends AbstractChange {
    private String schemaName;
    private String tableName;
    private String columnName;
    private String defaultNullValue;
    private String columnDataType;


    public AddNotNullConstraintChange() {
        super("addNotNullConstraint", "Add Not-Null Constraint", ChangeMetaData.PRIORITY_DEFAULT);
    }

    public String getSchemaName() {
        return schemaName;
    }

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

    public String getTableName() {
        return tableName;
    }

    public void setTableName(String tableName) {
        this.tableName = tableName;
    }

    public String getColumnName() {
        return columnName;
    }

    public void setColumnName(String columnName) {
        this.columnName = columnName;
    }

    public String getDefaultNullValue() {
        return defaultNullValue;
    }

    public void setDefaultNullValue(String defaultNullValue) {
        this.defaultNullValue = defaultNullValue;
    }

    public String getColumnDataType() {
        return columnDataType;
    }

    public void setColumnDataType(String columnDataType) {
        this.columnDataType = columnDataType;
    }

    public SqlStatement[] generateStatements(Database database) {

////        if (database instanceof SQLiteDatabase) {
//    		// return special statements for SQLite databases
//    		return generateStatementsForSQLiteDatabase(database);
//        }

        List<SqlStatement> statements = new ArrayList<SqlStatement>();
        String schemaName = getSchemaName() == null?database.getDefaultSchemaName():getSchemaName();

        if (defaultNullValue != null) {
            String defaultValue = defaultNullValue;

            if (getColumnDataType() != null && getColumnDataType().equalsIgnoreCase("BOOLEAN")) {
                BooleanType booleanType = TypeConverterFactory.getInstance().findTypeConverter(database).getBooleanType();
                if (defaultNullValue.equalsIgnoreCase("TRUE")) {
                    defaultValue = booleanType.getTrueBooleanValue();
                } else if (defaultNullValue.equalsIgnoreCase("FALSE")) {
                    defaultValue = booleanType.getFalseBooleanValue();
                }
            }

            statements.add(new UpdateStatement(schemaName, getTableName())
                    .addNewColumnValue(getColumnName(), defaultValue)
                    .setWhereClause(getColumnName() + " IS NULL"));
        }

        statements.add(new SetNullableStatement(schemaName, getTableName(), getColumnName(), getColumnDataType(), false));
        if (database instanceof DB2Database) {
            statements.add(new ReorganizeTableStatement(schemaName, getTableName()));
        }

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

    private SqlStatement[] generateStatementsForSQLiteDatabase(Database database) {

        // SQLite does not support this ALTER TABLE operation until now.
        // For more information see: http://www.sqlite.org/omitted.html.
        // This is a small work around...

        List<SqlStatement> statements = new ArrayList<SqlStatement>();

        String schemaName = getSchemaName() == null?database.getDefaultSchemaName():getSchemaName();
        if (defaultNullValue != null) {
            statements.add(new UpdateStatement(schemaName, getTableName())
                    .addNewColumnValue(getColumnName(), getDefaultNullValue())
                    .setWhereClause(getColumnName() + " IS NULL"));
        }

//		// ... test if column contains NULL values
//		if (defaultNullValue == null) {
//			List<Map> null_rows = null;
//			try {
//				null_rows = database.getExecutor().
//					queryForList(new RawSqlStatement(
//						"SELECT * FROM `"+
//						database.escapeTableName(getSchemaName(), getTableName())+
//						"` WHERE `"+getColumnName()+"` IS NULL;"));
//			} catch (DatabaseException e) {
//				e.printStackTrace();
//			}
//    		if (null_rows.size()>0) {
//    			throw new UnsupportedChangeException(
//    					"Failed to add a Not-Null-Constraint because " +
//    					"some values are null. Use the " +
//    					"defaultNullValue attribute to define default " +
//    					"values for the existing null values.");
//    		}
//    	}

        // define alter table logic
        AlterTableVisitor rename_alter_visitor = new AlterTableVisitor() {
            public ColumnConfig[] getColumnsToAdd() {
                return new ColumnConfig[0];
            }
            public boolean copyThisColumn(ColumnConfig column) {
                return true;
            }
            public boolean createThisColumn(ColumnConfig column) {
                if (column.getName().equals(getColumnName())) {
                    column.getConstraints().setNullable(false);
                }
                return true;
            }
            public boolean createThisIndex(Index index) {
                return true;
            }
        };

        try {
            // alter table
            statements.addAll(SQLiteDatabase.getAlterTableStatements(rename_alter_visitor, database,getSchemaName(),getTableName()));
        } catch (Exception e) {
            e.printStackTrace();
        }

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

    @Override
    protected Change[] createInverses() {
        DropNotNullConstraintChange inverse = new DropNotNullConstraintChange();
        inverse.setColumnName(getColumnName());
        inverse.setSchemaName(getSchemaName());
        inverse.setTableName(getTableName());
        inverse.setColumnDataType(getColumnDataType());

        return new Change[]{
                inverse
        };
    }

    public String getConfirmationMessage() {
        return "Null constraint has been added to " + getTableName() + "." + getColumnName();
    }
}