中文

dbChain js-client

---

dbChain js-client is the JavaScript implementation of the client side library of dbChain, the blockchain database. With the js-client, developers can quickly start a dbChain application in minutes.

The js-client provides JavaScript functions for

- Generating mnemonic and private/public key pairs
- Checking whether key exists
- Accessing passphrase
- Retrieving list of tables of a database
- Retrieving the options of a talbe
- Retrieving columns of a table
- Retrieving options of a column
- Inserting a row into a table
- Retrieving all rows of a table
- Searching for rows contain certain field value

Install

``shell
yarn add dbchain-js-client
`

or

`shell
npm install --save dbchain-js-client
`

Usage

#### Generating mnemonic and private/public key pais
`javascript
import { newMnemonic, createAndStoreKey } from "dbchain-js-client";

const mnemonic = newMnemonic();
// brown deliver ignore estate adjust pond final inject wear return sword silent
const passphrase = "123345678"
createAndStoreKey(mnemonic, passphrase)
`

#### Checking whether key exists
`javascript
import { hasKey } from 'dbchain-js-client;
if(!hasKey()) {
console.log("User needs to generate and save key pairs")
}
`

#### Accessing passphrase
`javascript
import { hasPassphrase, savePassphrase } from 'dbchain-js-client;

if(!hasPassphrase()) {
console.log("User needs to input passphrase");
}

// when user login with a passphrase, we usually save it to browser session storage
var passphrase = "12345678"
if (savePassphrase(passphrase)) {
console.log("passphrase saved successfully");
} else {
console.log("passphrase is invalid");
}
`

#### Retrieving list of tables of a database
`javascript
import { getTables } from "dbchain-js-client";

const appCode = "DJ1PGEQ45A";
const tables = await getTables(appCode);
/*
[
"supplier",
"product",
"customer"
]
*/
`

#### Retrieving the options of a table
`javascript
import { getTableOptions } from "dbchain-js-client";

const appCode = "DJ1PGEQ45A";
const tableName = "supplier";
const options = await getTableOptions(appCode, tableName);
/*
[
"public"
]
*/
`

#### Retrieving columns of a table
`javascript
import { getTable } from "dbchain-js-client";

const appCode = "DJ1PGEQ45A";
const tableName = "supplier";
const options = await getTable(appCode, tableName);
/*
[
"name",
"phone",
"address_id"
]
*/
`
#### Retrieving options of a column
`javascript
import { getFieldOptions } from "dbchain-js-client";

const appCode = "DJ1PGEQ45A";
const tableName = "supplier";
const fieldName = "phone";
const options = await getFieldOptions(appCode, tableName, fieldName);
/*
[
"not-null"
]
*/
`
#### Inserting a row into a table
`javascript
import { insertRow } from "dbchain-js-client";

const appCode = "DJ1PGEQ45A";
const tableName = "supplier";

var record = {};
record.name = "Super supplier"
record.phone = "18888888888";
record.address_id = "5";

const options = await insertRow(appCode, tableName, record, function() {
console.log("inserting record succeeded");
});
`

#### Retrieving id of all rows in a table
`javascript
import { getAllIds } from "dbchain-js-client";

const appCode = "DJ1PGEQ45A";
const tableName = "supplier";
const ids = await getAllIds(appCode, tableName);
/*
[
"1",
"2",
"3",
"4"
]
*/
`

#### Retrieving a row from a table
`javascript
import { getRow } from "dbchain-js-client";

const appCode = "DJ1PGEQ45A";
const tableName = "supplier";
const record = await getRow(appCode, tableName, "1");
/*
{
name: "Super supplier",
phone: "18888888888",
address_id: "5"
}
*/
``

License

dbChain js-client is licensed under the Apache-2.0 License.