package jef.database;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.concurrent.atomic.AtomicLong;
import jef.common.Entry;
import jef.database.dialect.DatabaseDialect;
import jef.database.innerpool.PartitionSupport;
import jef.database.jdbc.result.ResultSetContainer;
import jef.database.meta.Feature;
import jef.database.meta.ISelectProvider;
import jef.database.meta.MetaHolder;
import jef.database.query.ComplexQuery;
import jef.database.query.ConditionQuery;
import jef.database.query.ISelectItemProvider;
import jef.database.query.Join;
import jef.database.query.JoinElement;
import jef.database.query.OrderField;
import jef.database.query.Query;
import jef.database.query.SelectsImpl;
import jef.database.query.SingleColumnSelect;
import jef.database.query.SqlContext;
import jef.database.routing.PartitionResult;
import jef.database.support.MultipleDatabaseOperateException;
import jef.database.support.SqlLog;
import jef.database.wrapper.clause.BindSql;
import jef.database.wrapper.clause.CountClause;
import jef.database.wrapper.clause.GroupClause;
import jef.database.wrapper.clause.OrderClause;
import jef.database.wrapper.clause.QueryClause;
import jef.database.wrapper.clause.SelectPart;
import jef.database.wrapper.executor.DbTask;
import jef.database.wrapper.variable.BindVariableContext;
import jef.http.client.support.CommentEntry;
import jef.tools.ArrayUtils;
import jef.tools.PageLimit;
import jef.tools.StringUtils;
public abstract class SelectProcessor {
static SelectProcessor get(DatabaseDialect profile, DbClient db) {
return new PreparedImpl(db, db.preProcessor);
}
/**
* 转换为SQL查询语句
*
* @param obj
* 请求
* @param range
* 范围
* @param myTableName
* 自定义表名（排除）
* @param withOrder
* 带排序
* @return
*/
public abstract QueryClause toQuerySql(ConditionQuery obj, PageLimit range, boolean withOrder);
/**
* 形成count的语句 可以返回多个count语句，意味着要执行上述全部语句，然后累加
*
* @FIXME 目前看来，当设置了投影操作时，这种转换不太靠谱，需要进一步改进计算方式．比如用group子句来实现distinct操作。
*/
public abstract CountClause toCountSql(ConditionQuery obj) throws SQLException;
protected abstract void processSelect0(OperateTarget db, QueryClause sql, PartitionResult site, ConditionQuery queryObj, ResultSetContainer rs, QueryOption option, SqlLog debug) throws SQLException;
protected abstract long processCount0(OperateTarget db, BindSql bindSqls, SqlLog debug) throws SQLException;
protected DbClient db;
public SqlProcessor parent;
SelectProcessor(DbClient db, SqlProcessor parent) {
this.db = db;
this.parent = parent;
}
@Deprecated
public DatabaseDialect getProfile() {
return parent.getProfile();
}
public DatabaseDialect getProfile(PartitionResult[] sites) {
return this.parent.getProfile(sites);
}
public PartitionSupport getPartitionSupport() {
return db.getPartitionSupport();
}
final static class PreparedImpl extends SelectProcessor {
PreparedImpl(DbClient db, SqlProcessor parent) {
super(db, parent);
}
public QueryClause toQuerySql(ConditionQuery obj, PageLimit range, boolean order) {
QueryClause result = obj.toQuerySql(this, obj.prepare(), order);
result.setPageRange(range);
return result;
}
protected void processSelect0(OperateTarget db, QueryClause sqlResult, PartitionResult site, ConditionQuery queryObj, ResultSetContainer rs2, QueryOption option, SqlLog sb) throws SQLException {
// 计算查询结果集参数
if (option.holdResult && db.getProfile().has(Feature.TYPE_FORWARD_ONLY)) {
throw new UnsupportedOperationException("The database " + db.getProfile() + " can not support your 'selectForUpdate' operation.");
}
BindSql sql = sqlResult.getSql(site);
PreparedStatement psmt = null;
ResultSet rs = null;
sb.ensureCapacity(sql.getSql().length() + 150);
sb.append(sql.getSql()).append(db);
try {
psmt = db.prepareStatement(sql.getSql(), sql.getRsLaterProcessor(), option.holdResult);
BindVariableContext context = new BindVariableContext(psmt, db.getProfile(), sb);
context.setVariables(queryObj, null, sql.getBind());
option.setSizeFor(psmt);
rs = psmt.executeQuery();
rs2.add(rs, psmt, db);
} catch (SQLException e) {
DbUtils.close(rs);
DbUtils.close(psmt);
DbUtils.processError(e, ArrayUtils.toString(sqlResult.getTables(), true), db);
db.releaseConnection();
throw e;
} catch (RuntimeException e) {
DbUtils.close(rs);
DbUtils.close(psmt);
db.releaseConnection();
throw e;
} finally {
sb.output();
}
}
@Override
public CountClause toCountSql(ConditionQuery obj) throws SQLException {
if (obj instanceof Query<?>) {
Query<?> query = (Query<?>) obj;
CountClause cq = new CountClause();
String myTableName = (String) query.getAttribute("_table_name");
myTableName = MetaHolder.toSchemaAdjustedName(myTableName);
PartitionResult[] sites = DbUtils.toTableNames(query.getInstance(), myTableName, query, db.getPartitionSupport());
DatabaseDialect profile = getProfile(sites);
SqlContext context = query.prepare();
GroupClause groupClause = toGroupAndHavingClause(query, context, profile);
if (sites.length > 1) {// 多数据库下还要Distinct，没办法了
if (context.isDistinct()) {
throw new MultipleDatabaseOperateException("Not Supported, Count with 'distinct'");
} else if (groupClause.isNotEmpty()) {
throw new MultipleDatabaseOperateException("Not Supported, Count with 'group'");
}
}
BindSql result = parent.toWhereClause(query, context, null, profile,false);
if (context.isDistinct()) {
String countStr = toSelectCountSql(context.getSelectsImpl(), context, groupClause.isNotEmpty());
for (PartitionResult site : sites) {
for (String table : site.getTablesEscaped(db.getProfile(site.getDatabase()))) {
String sql = StringUtils.concat(countStr, table, " t", result.getSql(), groupClause.toString());
cq.addSql(site.getDatabase(), new BindSql(sql, result.getBind()));
}
}
} else {
for (PartitionResult site : sites) {
for (String table : site.getTablesEscaped(db.getProfile(site.getDatabase()))) {
String sql = StringUtils.concat("select count(*) from ", table, " t", result.getSql(), groupClause.toString());
cq.addSql(site.getDatabase(), new BindSql(sql, result.getBind()));
}
}
}
return cq;
} else if (obj instanceof Join) {
Join join = (Join) obj;
SqlContext context = join.prepare();
DatabaseDialect profile = getProfile();
GroupClause groupClause = toGroupAndHavingClause(join, context, profile);
CountClause cq = new CountClause();
String countStr;
if (context.isDistinct()) {
countStr = toSelectCountSql(context.getSelectsImpl(), context, groupClause.isNotEmpty());
} else {
countStr = "select count(*) from ";
}
BindSql result = parent.toWhereClause(join, context, null, profile, false);
result.setSql(countStr + join.toTableDefinitionSql(parent, context, profile,false) + result.getSql() + groupClause);
cq.addSql(null, result);
return cq;
} else if (obj instanceof ComplexQuery) {
ComplexQuery cq = (ComplexQuery) obj;
SqlContext context = cq.prepare();
return cq.toPrepareCountSql(this, context);
} else {
throw new IllegalArgumentException();
}
}
private String toSelectCountSql(SelectsImpl selectsImpl, SqlContext context, boolean groupMode) {
if (selectsImpl == null) {
return "select count(distinct *) from ";
}
List<ISelectItemProvider> items = selectsImpl.getReference();
if (items.isEmpty() || items.get(0).isAllTableColumns()) {
return "select count(distinct *) from ";
}
StringBuilder sb = new StringBuilder("select count(distinct ");
int distinctItemCount = 0;
for (ISelectItemProvider item : items) {
CommentEntry[] ces = item.getSelectColumns(getProfile(), groupMode, context);
for (CommentEntry ce : ces) {
if (distinctItemCount > 0) {
sb.append(',');
}
sb.append(ce.getKey());
distinctItemCount++;
}
}
sb.append(") from ");
return sb.toString();
}
@Override
protected long processCount0(OperateTarget db, BindSql bsql, SqlLog sb) throws SQLException {
long total = 0;
PreparedStatement psmt = null;
String sql = bsql.getSql();
ResultSet rs = null;
sb.append(sql).append(db);
long currentCount = 0;
try {
psmt = db.prepareStatement(sql);
psmt.setQueryTimeout(ORMConfig.getInstance().getSelectTimeout());
BindVariableContext context = new BindVariableContext(psmt, db.getProfile(), sb);
context.setVariables(null, null, bsql.getBind());
rs = psmt.executeQuery();
if (rs.next()) {
currentCount = rs.getLong(1);
sb.append("\tCount=").append(currentCount);
total += currentCount;
}
} catch (SQLException e) {
DbUtils.processError(e, sql, db);
throw e;
} finally {
sb.output();
DbUtils.close(rs);
DbUtils.close(psmt);
db.releaseConnection();
}
return total;
}
}
public static OrderClause toOrderClause(ConditionQuery obj, SqlContext context, DatabaseDialect profile) {
if (obj.getOrderBy() == null || obj.getOrderBy().size() == 0) {
return OrderClause.DEFAULT;
}
List<Entry<String, Boolean>> rs = new ArrayList<Entry<String, Boolean>>();
StringBuffer sb = new StringBuffer();
for (OrderField e : obj.getOrderBy()) {
if (sb.length() > 0) {
sb.append(",");
}
String orderResult = e.toString(profile, context);
sb.append(orderResult).append(' ');
sb.append(e.isAsc() ? "ASC" : "DESC");
rs.add(new Entry<String, Boolean>(orderResult, e.isAsc()));
}
return new OrderClause(" order by " + sb.toString(), rs);
}
// 转为group + having语句
public static GroupClause toGroupAndHavingClause(JoinElement q, SqlContext context, DatabaseDialect profile) {
GroupClause result = new GroupClause();
for (ISelectItemProvider table : context.getReference()) {
if (table.getReferenceCol() == null)
continue;
for (ISelectProvider field : table.getReferenceCol()) {
if (field instanceof SingleColumnSelect) {
SingleColumnSelect column = (SingleColumnSelect) field;
if ((column.getProjection() & ISelectProvider.PROJECTION_GROUP) > 0) {
result.addGroup(column.getSelectItem(profile, table.getSchema(), context));
}
if ((column.getProjection() & ISelectProvider.PROJECTION_HAVING) > 0) {
result.addHaving(column.toHavingClause(profile, table.getSchema(), context));
} else if ((column.getProjection() & ISelectProvider.PROJECTION_HAVING_NOT_SELECT) > 0) {
result.addHaving(column.toHavingClause(profile, table.getSchema(), context));
}
}
}
}
return result;
}
/**
* 返回SQL的Select列部分,本来JDBC规定接口ResultsetMetadata中可以getTableName(int
* columnIndex)来获得某个列的表名 但是大多数JDBC驱动都没有实现，返回的是""。 为此，需要对所有字段进行唯一化编码处理
*/
public static SelectPart toSelectSql(SqlContext context, GroupClause group, DatabaseDialect profile) {
boolean groupMode = group.isNotEmpty();
SelectPart rs = new SelectPart();
rs.setDistinct(context.isDistinct());
for (ISelectItemProvider rp : context.getReference()) {// 每个rp就是一张表
rs.addAll(rp.getSelectColumns(profile, groupMode, context));
}
if (!groupMode && profile.has(Feature.SELECT_ROW_NUM) && context.size() == 1) {
ISelectItemProvider ip = context.getReference().get(0);
if (ip.isAllTableColumns()) {
rs.add(new CommentEntry("t.rowid", "rowid_"));
}
}
return rs;
}
void processSelect(final QueryClause sql, final Session session, final ConditionQuery queryObj, final ResultSetContainer rs, final QueryOption option, int mustTx) throws SQLException {
if (sql.isMultiDatabase()) {
if (sql.getTables().length >= ORMConfig.getInstance().getParallelSelect()) {// 启用并行查询
List<DbTask> tasks = new ArrayList<DbTask>();
for (final PartitionResult site : sql.getTables()) {
final SqlLog debug = ORMConfig.getInstance().newLogger();
tasks.add(new DbTask() {
public void execute() throws SQLException {
processSelect0(session.selectTarget(site.getDatabase()), sql, site, queryObj, rs, option, debug);
}
});
}
DbUtils.parallelExecute(tasks);
} else {
final SqlLog debug = ORMConfig.getInstance().newLogger();
for (PartitionResult site : sql.getTables()) {
processSelect0(session.selectTarget(site.getDatabase()), sql, site, queryObj, rs, option, debug);
}
}
sql.parepareInMemoryProcess(null, rs);
} else {
// 如果是结果集持有的，那么必须在事务中
PartitionResult site = sql.getTables()[0];
OperateTarget target = session.wrapTarget(site.getDatabase(), mustTx);
processSelect0(target, sql, site, queryObj, rs, option, ORMConfig.getInstance().newLogger());
}
}
long processCount(Session session, CountClause sqls) throws SQLException {
if (sqls.getSqls().size() >= ORMConfig.getInstance().getParallelSelect()) {
final AtomicLong total = new AtomicLong();
List<DbTask> tasks = new ArrayList<DbTask>();
for (final Map.Entry<String, List<BindSql>> sql : sqls.getSqls().entrySet()) {
final SqlLog debug = ORMConfig.getInstance().newLogger();
final OperateTarget target = session.selectTarget(sql.getKey());
tasks.add(new DbTask() {
@Override
public void execute() throws SQLException {
for (BindSql bs : sql.getValue()) {
total.addAndGet(processCount0(target, bs, debug));
}
}
});
}
DbUtils.parallelExecute(tasks);
return total.get();
} else {
long total = 0;
final SqlLog debug = ORMConfig.getInstance().newLogger();
for (Map.Entry<String, List<BindSql>> sql : sqls.getSqls().entrySet()) {
OperateTarget target = session.selectTarget(sql.getKey());
for (BindSql bs : sql.getValue()) {
total += processCount0(target, bs, debug);
}
}
debug.output();
return total;
}
}
}