package org.nutz.dao.impl.jdbc.db2;
import org.nutz.dao.DB;
import org.nutz.dao.Dao;
import org.nutz.dao.Sqls;
import org.nutz.dao.entity.Entity;
import org.nutz.dao.entity.MappingField;
import org.nutz.dao.entity.PkType;
import org.nutz.dao.impl.jdbc.AbstractJdbcExpert;
import org.nutz.dao.jdbc.JdbcExpertConfigFile;
import org.nutz.dao.pager.Pager;
import org.nutz.dao.sql.Pojo;
import org.nutz.dao.util.Pojos;
public class Db2JdbcExpert extends AbstractJdbcExpert {
public Db2JdbcExpert(JdbcExpertConfigFile conf) {
super(conf);
}
public String getDatabaseType() {
return DB.DB2.name();
}
// TODO not tested!!
public boolean createEntity(Dao dao, Entity<?> en) {
StringBuilder sb = new StringBuilder("CREATE TABLE " + en.getTableName() + "(");
// 创建字段
for (MappingField mf : en.getMappingFields()) {
sb.append('\n').append(mf.getColumnName());
sb.append(' ').append(evalFieldType(mf));
// 非主键的 @Name，应该加入唯一性约束
if (mf.isName() && en.getPkType() != PkType.NAME) {
sb.append(" UNIQUE NOT NULL");
}
// 普通字段
else {
if (mf.isNotNull() || mf.isPk())
sb.append(" NOT NULL");
if (mf.hasDefaultValue())
sb.append(" DEFAULT '").append(mf.getDefaultValue(null)).append('\'');
if (mf.isAutoIncreasement())
sb.append(" generated by default as identity ");
if (mf.isPk() && en.getPks().size() == 1) {
sb.append(" primary key ");
}
}
sb.append(',');
}
// 创建索引
// TODO ...
// 结束表字段设置
sb.setCharAt(sb.length() - 1, ')');
// 执行创建语句
dao.execute(Sqls.create(sb.toString()));
// 创建联合主键
if (en.getPks().size() > 1) {
sb = new StringBuilder();
sb.append("ALTER TABLE ")
.append(en.getTableName())
.append(" ADD CONSTRAINT PK");
for (MappingField mf : en.getPks()) {
sb.append("_").append(mf.getColumnName());
}
sb.append(" PRIMARY KEY (");
for (MappingField mf : en.getPks()) {
sb.append(mf.getColumnName()).append(",");
}
sb.setCharAt(sb.length() - 1, ')');
dao.execute(Sqls.create(sb.toString()));
}
// 创建关联表
createRelation(dao, en);
return true;
}
@Override
protected String evalFieldType(MappingField mf) {
switch (mf.getColumnType()) {
case BOOLEAN:
return "SMALLINT";
case INT:
// 用户自定义了宽度
// if (mf.getWidth() > 0)
// return "decimal(" + mf.getWidth() + ")";
// 用数据库的默认宽度
return "INTEGER";
case FLOAT:
// 用户自定义了精度
if (mf.getWidth() > 0 && mf.getPrecision() > 0) {
return "decimal(" + mf.getWidth() + "," + mf.getPrecision() + ")";
}
// 用默认精度
if (mf.getTypeMirror().isDouble())
return "decimal(15,10)";
return "FLOAT";
}
return super.evalFieldType(mf);
}
public void formatQuery(Pojo pojo) {
Pager pager = pojo.getContext().getPager();
// 需要进行分页
if (null != pager) {
// 之前插入
pojo.insertFirst(Pojos.Items.wrap("SELECT * FROM ("
+ "SELECT ROW_NUMBER() OVER() AS ROWNUM, "
+ "T.* FROM ("));
// 之后插入
pojo.append(Pojos.Items.wrapf( ") T) AS A WHERE ROWNUM BETWEEN %d AND %d",
pager.getOffset() + 1,
pager.getOffset() + pager.getPageSize()));
}
}
}