Blockchain as a Service:Query Interface

The contract platform provides multiple query operations for you to query blocks, transactions, accounts, and contracts.

Query block headers

You can call the QueryBlockHeader operation to query a specified block header. You can use the block height number or the block hash hash to query the target block header.

Request parameters

One of these two parameters must be used.

Example 1

Query a block using the block height.

chain.ctr.QueryBlockHeader({
  block_number: 30, // Specify the value of the block height based on your business requirements.
}, (err, data) => {
  console.log(data)
})

Example 2

Query a block using the block hash.

chain.ctr.QueryBlockHeader({
  hash: '0xe6eebd5b7a6eff8f0af9ac151160e59cc7ec98429822400fc78906c3895bc1aa', // Specify the block hash based on your business requirements.
}, (err, data) => {
  console.log(data)
})

Query blocks

QueryLastBlock

You can call this operation to query the last block. This operation does not require any request parameters.

Examples

chain.ctr.QueryLastBlock({}, (err, data) => {
  console.log(data)
})

QueryBlock

You can call this operation to query a specified block header. You can use the block height number or the block hash hash to query the target block header.

Request parameters

Example 1

Query a block using the block height.

chain.ctr.QueryBlock({
  block_number: 30, // Specify the value of the block height based on your business requirements
}, (err, data) => {
  console.log(data)
})

Example 2

Query a block using the block hash.

chain.ctr.QueryBlock({
  hash: '0xe6eebd5b7a6eff8f0af9ac151160e59cc7ec98429822400fc78906c3895bc1aa', // Specify the block hash based on your business requirements
}, (err, data) => {
  console.log(data)
})

Query transactions

You can call the QueryTransaction operation to query a transaction using the transaction hash.

Request parameters

Examples

chain.ctr.QueryTransaction({
  hash: '0xf66621372a13c813fe978c060e11a93c28b75f90d2200b9fa700f21433a96a77' //Specify the value based on your business requirements
}, (err, data) => {
  console.log('QueryTransaction:', data)
})

Query receipts

You can call the QueryTransactionReceipt operation to query a transaction receipt using the transaction hash.

Request parameters

Examples

chain.ctr.QueryTransactionReceipt({
  hash: '0xf66621372a13c813fe978c060e11a93c28b75f90d2200b9fa700f21433a96a77' //Specify the value based on your business requirements
}, (err, data) => {
  console.log('QueryTransactionReceipt:', data)
})

Query accounts

You can call the QueryAccount operation to query a specified account. The name of the account is required. The hash value of thename is the identity of the target account. You can also directly provide a hexadecimal string prefixed with “0x” as the identity of the target account.

Request parameters

Example 1

Use the account name.

chain.ctr.QueryAccount({
  from: 'Tester001'
}, (err, data) => {
  console.log('QueryAccount:', data)
})

Example 2

Use the identity of the target account. The identity is represented by a hexadecimal string.

chain.ctr.QueryAccount({
  from: '0xc60a9d48105950a0cca07a4c6320b98c303ad42d694a634529e8e1a0a16fcdb5'
}, (err, data) => {
  console.log('QueryAccount:', data)
})

Query contract accounts

You can call the QueryContract operation to query a specified contract account. The name of the target contract is required. The hash value of the name is the identity of the target contract. You can also directly provide a hexadecimal string prefixed with “0x” as the identity of the target contract.

Request parameters

The following parameters are encapsulated and passed in as an object.

Examples

contractName = 'contract'+Date.now()
let myContract = chain.ctr.contract(contractName, abi)
myContract.new(bytecode, {
  from: 'Tester001'
}, (err, contract, data) => {
  console.log('contract deploy result:', data)
  // Query the deployed contract
  chain.ctr.QueryContract({
    from: contractName
  }, (err, data) => {
    console.log('QueryContract:', data)
  })
})