org.iworkz.habitat.dialect.DatabaseDialect Maven / Gradle / Ivy

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A lightweight Java library for simple database access.
There is a newer version: 1.0.30
package org.iworkz.habitat.dialect;

import java.lang.reflect.Type;

import javax.inject.Singleton;

import org.iworkz.habitat.entity.EntityDefinition;
import org.iworkz.habitat.entity.EntityFieldDefinition;
import org.iworkz.habitat.entity.FieldValueStrategy;

@Singleton
public class DatabaseDialect {

	public String getTypeName(EntityFieldDefinition entityFieldDefinition) {
		switch (entityFieldDefinition.getType()) {
		case NUMBER:
			return "NUMBER";
		case VARCHAR:
			return "VARCHAR";
		case DATE:
			return "DATE";
		case BLOB:
			return "BLOB";
		}
		throw new RuntimeException("Type name not defined for type " + entityFieldDefinition.getType());
	}

	public String getConstraintsSql(EntityFieldDefinition entityFieldDefinition) {
		Integer constraint1 = entityFieldDefinition.getConstraint1();
		Integer constraint2 = entityFieldDefinition.getConstraint2();
		if (constraint1 != null && constraint1 > 0) {
			if (constraint2 != null && constraint2 > 0) {
				return "(" + constraint1 + "," + constraint2 + ")";
			} else {
				return "(" + constraint1 + ")";
			}
		}
		return "";
	}
	
	public String buildDropTableIfExistsStatement(EntityDefinition table) {
		 return "DROP TABLE IF EXISTS " + table.getName() + ";";
	}
	
	public String buildCreateTableIfExistsStatement(EntityDefinition table, boolean onlyIfNotExists) {
        StringBuilder sql = new StringBuilder();
        sql.append("CREATE TABLE ");
        if (onlyIfNotExists) {
            sql.append("IF NOT EXISTS ");
        }
        sql.append(table.getName() + "(");
        table.appendFieldDefinitionsSql(sql);
        table.appendPrimaryKeySqL(sql);
        sql.append(")");
        return sql.toString();
	}
	
	public void appendFieldDefinitionsSql(StringBuilder sql, EntityDefinition table) {
		boolean first = true;
		for (EntityFieldDefinition f : table.getFields()) {
			StringBuilder command = new StringBuilder();
			if (!first) {
				command.append(", ");
			} else {
				first = false;
			}
			command.append(f.getName());
			command.append(" ");
			command.append(f.getTypeName());
			command.append(f.getConstraintsSql());
			if (f.getValueStrategy() == FieldValueStrategy.AUTO) {
				command.append(" auto_increment");
			}
			command.append(f.getNotNullSql());

			sql.append(command.toString());
		}
		if (!table.getPrimaryKey().isEmpty()) {
			sql.append(", ");
		}
	}
	
    public void appendPrimaryKeySqL(StringBuilder sql, EntityDefinition table) {
        if (!table.getPrimaryKey().isEmpty()) {
            sql.append("PRIMARY KEY (");
            for (EntityFieldDefinition p : table.getPrimaryKey()) {
                sql.append(p.getName());
            }
            sql.append(")");
        }
    }

	public Integer getDefaultPrecision(Type javaType) {
		return null;
	}

	public Integer getDefaultScale(Type javaType) {
		return 0;
	}

}