package liquibase.sqlgenerator.core;
import liquibase.database.Database;
import liquibase.database.core.DB2Database;
import liquibase.database.core.DerbyDatabase;
import liquibase.database.core.FirebirdDatabase;
import liquibase.database.core.H2Database;
import liquibase.database.core.HsqlDatabase;
import liquibase.database.core.InformixDatabase;
import liquibase.database.core.OracleDatabase;
import liquibase.database.core.SybaseASADatabase;
import liquibase.database.core.SybaseDatabase;
import liquibase.datatype.DataTypeFactory;
import liquibase.exception.ValidationErrors;
import liquibase.sqlgenerator.SqlGeneratorChain;
import liquibase.statement.AutoIncrementConstraint;
import liquibase.statement.core.AddColumnStatement;
public class AddColumnGeneratorDefaultClauseBeforeNotNull extends AddColumnGenerator {
@Override
public int getPriority() {
return PRIORITY_DATABASE;
}
@Override
public boolean supports(AddColumnStatement statement, Database database) {
return database instanceof OracleDatabase
|| database instanceof HsqlDatabase
|| database instanceof H2Database
|| database instanceof DerbyDatabase
|| database instanceof DB2Database
|| database instanceof FirebirdDatabase
|| database instanceof SybaseDatabase
|| database instanceof SybaseASADatabase
|| database instanceof InformixDatabase;
}
@Override
public ValidationErrors validate(AddColumnStatement statement, Database database, SqlGeneratorChain sqlGeneratorChain) {
ValidationErrors validationErrors = super.validate(statement, database, sqlGeneratorChain);
if (statement.isMultiple()) {
for (AddColumnStatement column : statement.getColumns()) {
validateSingleColumn(column, database, validationErrors);
}
} else {
validateSingleColumn(statement, database, validationErrors);
}
return validationErrors;
}
private void validateSingleColumn(AddColumnStatement statement,
Database database, ValidationErrors validationErrors) {
if (database instanceof DerbyDatabase && statement.isAutoIncrement()) {
validationErrors.addError("Cannot add an identity column to derby");
}
}
@Override
protected String generateSingleColumnSQL(AddColumnStatement statement,
Database database) {
String alterTable = " ADD " + database.escapeColumnName(statement.getCatalogName(), statement.getSchemaName(), statement.getTableName(), statement.getColumnName()) + " " + DataTypeFactory.getInstance().fromDescription(statement.getColumnType() + (statement.isAutoIncrement() ? "{autoIncrement:true}" : ""), database).toDatabaseDataType(database);
alterTable += getDefaultClause(statement, database);
if (primaryKeyBeforeNotNull(database)) {
if (statement.isPrimaryKey()) {
alterTable += " PRIMARY KEY";
}
}
if (statement.isAutoIncrement()) {
AutoIncrementConstraint autoIncrementConstraint = statement.getAutoIncrementConstraint();
alterTable += " " + database.getAutoIncrementClause(autoIncrementConstraint.getStartWith(), autoIncrementConstraint.getIncrementBy());
}
if (!statement.isNullable()) {
alterTable += " NOT NULL";
} else if (database instanceof SybaseDatabase || database instanceof SybaseASADatabase) {
alterTable += " NULL";
}
if (!primaryKeyBeforeNotNull(database)) {
if (statement.isPrimaryKey()) {
alterTable += " PRIMARY KEY";
}
}
return alterTable;
}
private String getDefaultClause(AddColumnStatement statement, Database database) {
String clause = "";
Object defaultValue = statement.getDefaultValue();
if (defaultValue != null) {
clause += " DEFAULT " + DataTypeFactory.getInstance().fromObject(defaultValue, database).objectToSql(defaultValue, database);
}
return clause;
}
private boolean primaryKeyBeforeNotNull(Database database) {
return !(database instanceof HsqlDatabase || database instanceof H2Database);
}
}