/**
* 对Desc语句进行分析 返回数据路由集合
*
* @param schema 数据库名
* @param rrs 数据路由集合
* @param stmt 执行语句
* @param ind 第一个' '的位置
* @return RouteResultset(数据路由集合)
* @author mycat
*/
private static RouteResultset analyseDescrSQL(
SchemaConfig schema, RouteResultset rrs, String stmt, int ind) {
int[] repPos = {ind, 0};
String tableName = RouterUtil.getTableName(stmt, repPos);
stmt = stmt.substring(0, ind) + tableName + stmt.substring(repPos[1]);
RouterUtil.routeForTableMeta(rrs, schema, tableName, stmt);
return rrs;
}
/**
* 根据show语句获取数据路由集合
*
* @param schema 数据库名
* @param rrs 数据路由集合
* @param stmt 执行的语句
* @return RouteResultset数据路由集合
* @throws SQLSyntaxErrorException
* @author mycat
*/
public RouteResultset analyseShowSQL(SchemaConfig schema, RouteResultset rrs, String stmt)
throws SQLSyntaxErrorException {
String upStmt = stmt.toUpperCase();
int tabInd = upStmt.indexOf(" TABLES");
if (tabInd > 0) { // show tables
int[] nextPost = getSpecPos(upStmt, 0);
if (nextPost[0] > 0) { // remove db info
int end = getSpecEndPos(upStmt, tabInd);
if (upStmt.indexOf(" FULL") > 0) {
stmt = "SHOW FULL TABLES" + stmt.substring(end);
} else {
stmt = "SHOW TABLES" + stmt.substring(end);
}
}
return routeToMultiNode(schema, false, false, null, rrs, schema.getMetaDataNodes(), stmt);
}
// show index or column
int[] indx = getSpecPos(upStmt, 0);
if (indx[0] > 0) {
// has table
int[] repPos = {indx[0] + indx[1], 0};
String tableName = RouterUtil.getTableName(stmt, repPos);
// IN DB pattern
int[] indx2 = getSpecPos(upStmt, indx[0] + indx[1] + 1);
if (indx2[0] > 0) { // find LIKE OR WHERE
repPos[1] = getSpecEndPos(upStmt, indx2[0] + indx2[1]);
}
stmt = stmt.substring(0, indx[0]) + " FROM " + tableName + stmt.substring(repPos[1]);
RouterUtil.routeForTableMeta(rrs, schema, tableName, stmt);
return rrs;
}
// show create table tableName
int[] createTabInd = getCreateTablePos(upStmt, 0);
if (createTabInd[0] > 0) {
int tableNameIndex = createTabInd[0] + createTabInd[1];
if (upStmt.length() > tableNameIndex) {
String tableName = stmt.substring(tableNameIndex).trim();
int ind2 = tableName.indexOf('.');
if (ind2 > 0) {
tableName = tableName.substring(ind2 + 1);
}
RouterUtil.routeForTableMeta(rrs, schema, tableName, stmt);
return rrs;
}
}
return RouterUtil.routeToSingleNode(rrs, schema.getRandomDataNode(), stmt);
}