tikv
/
client-java
mirror of https://github.com/tikv/client-java.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

modify readme (#11)

This commit is contained in:
birdstorm 2018-12-10 17:10:08 +08:00 committed by GitHub
parent a93e507126
commit 3027bd76bc
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 1 additions and 58 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

59
README.md
View File

@ -37,64 +37,7 @@ make test
this project is designed to hook with `pd` and `tikv` which you can find in `PingCap` github page.
When you work with this project, you have to communicate with `pd` and `tikv`. There is a script taking care of this. By executing the following commands, `pd` and `tikv` can be executed on background.
```
cd scripts
make pd
make tikv
```
## How to use for now
Since it's not quite complete, a usage sample for now can be given is:
```java
// Init tidb cluster configuration
TiConfiguration conf = TiConfiguration.createDefault("127.0.0.1:2379");
TiSession session = TiSession.create(conf);
Catalog cat = session.getCatalog();
TiDBInfo db = cat.getDatabase("tpch_test");
TiTableInfo table = cat.getTable(db, "customer");
Snapshot snapshot = session.createSnapshot();
// Generate select ranges
ByteString startKey = TableCodec.encodeRowKeyWithHandle(table.getId(), Long.MIN_VALUE);
ByteString endKey = TableCodec.encodeRowKeyWithHandle(table.getId(), Long.MAX_VALUE);
Coprocessor.KeyRange keyRange = Coprocessor.KeyRange.newBuilder().setStart(startKey).setEnd(endKey).build();
List<Coprocessor.KeyRange> ranges = new ArrayList<>();
ranges.add(keyRange);
// Create select request
TiSelectRequest selectRequest = new TiSelectRequest();
selectRequest.addRanges(ranges);
selectRequest.addField(TiColumnRef.create("c_mktsegment", table));
selectRequest.setTableInfo(table);
selectRequest.setStartTs(session.getTimestamp().getVersion());
selectRequest.addWhere(new GreaterEqual(TiConstant.create(5), TiConstant.create(5)));
selectRequest.addGroupByItem(TiByItem.create(TiColumnRef.create("c_mktsegment"), false));
selectRequest.setLimit(10);
selectRequest.bind();
// Fetch data
Iterator<Row> iterator = snapshot.select(selectRequest);
System.out.println("Show result:");
while (iterator.hasNext()) {
Row rowData = iterator.next();
for (int i = 0; i < rowData.fieldCount(); i++) {
System.out.print(rowData.get(i, null) + "\t");
}
System.out.println();
}
```
Result:
```java
Show result:
BUILDING
AUTOMOBILE
MACHINERY
HOUSEHOLD
FURNITURE
```
When you work with this project, you have to communicate with `pd` and `tikv`. Please run TiKV and PD in advance.
## Raw TiKV-Client in Java
Java Implementation of Raw TiKV-Client