MindLake.DataLake

1. query() Method

Execute a SQL query or command.

When referencing a table in your SQL query statement, you can specify the table owner with their wallet address, like this: SELECT * FROM someWalletAddress.someTable. If you omit the wallet address in your query, it defaults to your own wallet address. For example, SELECT * FROM myTable is equivalent to SELECT * FROM myWalletAddress.myTable.

During testing, SQL queries will timeout after 5 minutes. Requests that take longer than that to process will not receive a response.

To specify an upper-case or mixed-case name of table or column, you need to double-quote the name; else it will be folded to lower case.

const result = await mindLake.dataLake.query(statement);

Parameters

1. statement - string: the SQL statement used to query Mind Lake, such as SELECT, INSERT, UPDATE, and CREATE.

Returns

An object of Promise<>. For more information.

• result - QueryResult: The result of query execution.

  type QueryResult = {
    data: Array<Array<any>>,
    columnList: Array<string>
  }

  • data - Array<Array<any>>: The query data result is presented as a 2D array, with rows and columns.

  • columnList - Array<string>: the column names in the specific order in which they appear.

Example

  const selectSql = `select * from wallet_balance`;
  const res = await dataLake.query(selectSql);
  if(res.code !== 0) {
    console.error(res.message);
    return
  }
  const columnList = res.result.columnList;
  for (const row of res.result.data) {
    for (const idx in row) {
     console.log(`${columnList[idx]} >>>`, row[idx])
    }
  }

2. createTable() Method

Create a table in the user's own account in Mind Lake.

const result = await mindLake.dataLake.createTable(tableName, columns, primaryKey)

Parameters

1. tableName - string: the name of the table to be created.

2. columns - Array<Column>: defines the columns in the table. Each column should be defined as a MindLake.DataLake.Column object.

3. primaryKey (Optional) - Array<string>|undefined: defines the table's primary key by specifying one or more columns. Each column in the primary key should be identified by its column name. If the primaryKey parameter is omitted, no primary key will be defined for the table.

Returns

An object of Promise<>. For more information.

Example

  const dataLake = mindLake.dataLake;
  const res = await dataLake.createTable("wallet_balance", [{columnName: 'WalletAddress', type: DataType.text, encrypt: false}, {columnName: 'Name', type: DataType.text, encrypt: true}, {columnName: 'Balance', type: DataType.float4, encrypt: true}], ["id"]);
  if(res.code !==0) {
    console.error(res.message);
    return
  }

3. MindLake.DataLake.Column

Column type is used to represent a single column in a table. Each Column instance encapsulates properties about the column, including its name, data type, and encryption status. By creating a Column object, you can define the properties of a table column and use it to construct a table schema.

Fields

• columnName - string: The name of the column.

• type - MindLake.DataType: The data type of the column, which should be define as MindLake.DataType

• encrypt - boolean: A flag that indicates whether the column should be encrypted or not.

Example

const column = {columnName: 'WalletAddress', type: MindLake.DataType.text, encrypt: false}

4. listTablesByCocoon() Method

Retrieve a list of names for the tables that belong to the user invoking the method, or in the specified cocoon.

await dataLake.listTableByCocoon(cocoonName)

Parameters

1. cocoonName (Optional) - string: specifies the name of the cocoon for which a list of tables should be returned. If the cocoonName parameter is omitted, all the tables that belong to the method caller will be listed.

Returns

An object of Promise<>. For more information.

• result - Array<string>: a list of names for the tables that belong to the user invoking the method, or in the specified cocoon.

Example

const result = await mindLake.dataLake.listTableByCocoon("cocoonName");

5. createCocoon() Method

Create a Cocoon in Mind Lake. Tables can be categorized into cocoons for classification purposes.

await mindLake.dataLake.createCocoon(cocooName)

Parameters

1. cocoonName - string: the name of the cocoon to be created.

Returns

An object of Promise<>. For more information.

Example

const result = await mindLake.dataLake.createCocoon("cocoonName");

6. listCocoon() Method

Retrieve a list of names for the cocoons that belong to the user invoking the method.

await mindLake.dataLake.listCocoon()

Returns

An object of Promise<>. For more information.

• result - Array<string>: a list of names for the cocoons that belong to the user invoking the method.

Example

const result = await mindLake.dataLake.listCocoon();

7. linkTableToCocoon() Method

Assign the specified cocoon tag to the table.

await mindLake.dataLake.linkTableToCocoon(tableName, cocoonName)

Parameters

1. tableName - string: the name of the table to be tagged with.

2. cocoonName - string: specifies the name of the cocoon for which the table should be tagged with.

Returns

An object of Promise<>. For more information.

Example

const result = await mindLake.dataLake.linkTableToCocoon("tableName", "cocoonName");

8. dropCocoon() Method

Delete a Cocoon in Mind Lake.

await mindLake.dataLake.dropCocoon(cocoonName)

Parameters

1. cocoonName - string: the name of the cocoon to be dropped.

Returns

An object of Promise<>. For more information.

Example

const result = await mindLake.dataLake.dropCocoon("cocoonName");

9. dropTable() Method

Drop a table in the user's own account in Mind Lake.

await mindLake.dataLake.dropTable(tableName)

Parameters

1. tableName - string: the name of the table to be dropped.

Returns

An object of Promise<>. For more information.

Example

const result = await mindLake.dataLake.dropTable("tableName");