Cassandra 错误：尽管 Javascript 中大小写一致，但由于似乎区分大小写，未定义列名

Question

我在一个 javascript 文件中执行了一条 Cassandra SQL 语句，其中包含多个参数，包括 networkInterfaces TEXT：

client.execute("CREATE TABLE IF NOT EXISTS testdb.networkData (latitude DOUBLE, longitude DOUBLE, allowsVoIP BOOLEAN, speed DOUBLE, uuid TEXT, timestamp TIMESTAMP PRIMARY KEY, networkType TEXT, carrierName TEXT, altitude DOUBLE, macAddress TEXT, publicIP TEXT, ssidLabel TEXT, networkInterfaces TEXT)", function (err, result) {
    if (!err){
        if ( result.rowLength > 0 ) {
            var data = result.rows[0];
            console.log("Total rows : "+ data.count);
        } else {
            console.log("No rows");
        }
    }else{
        console.log("count results err : "+err);
    }
});

在出现 networkInterfaces 的所有其他实例中使用相同的情况“networkInterfaces”。这包括向表中插入数据的代码：

// TODO: Save LAN interfaces as well
const recordCommand = 'INSERT INTO testdb.networkData (latitude, longitude, allowsVoIP, speed, uuid, timestamp, networkType, carrierName, altitude, macAddress, publicIP, ssidLabel, networkInterfaces) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)';
const params = [
    request.body.latitude,
    request.body.longitude,
    request.body.allowsVoIP,
    request.body.speed,
    request.body.uuid,
    request.body.timestamp,
    request.body.networkType,
    request.body.carrierName,
    request.body.altitude,
    request.body.macAddress,
    request.body.publicIP,
    request.body.ssidLabel,
    request.body.networkInterfaces
];

client.execute(recordCommand, params, { prepare: true }, function (error) {
    assert.ifError(error);
    //Inserted in the cluster
  });

然而，当命令被执行时，它说有一个未处理的错误如下：

错误：未定义的列名网络接口

未定义的列名似乎是大小写不匹配，但 networkInterfaces 的所有实例都具有相同的大小写。会不会有其他问题？

Answer 1

默认情况下，Cassandra 会将所有表/列名称转换为小写。 如果需要区分大小写的表/列名，请将其括在双引号中。 使用desc table_name检查表详细信息。

Eg:
Create table test(Column1 text primary key,"Column2" text);
 will result in cassandra table with 2 columns (column1 [Note all are lower case] and Column2 [C is uppercase])

Answer 2

这是更正脚本的示例。这里我的键空间名称是 yupoint。

CREATE TABLE IF NOT EXISTS yupoint.user (
    id text,
    login text,
    password text,
    firstname text,
    lastname text,
    email text,
    activated boolean,
    lang_key text,
    activation_key text,
    reset_key text,
    reset_date timestamp,
    authorities set<text>,;
    PRIMARY KEY(id)
);

CREATE TABLE IF NOT EXISTS yupoint.user_by_login (
    login text,
    id text,
    PRIMARY KEY(login, id)
);

现在更改使用您的键空间并创建一些记录。

使用yupoint；

yupoint>INSERT INTO user (id, login, password , firstname, lastname ,email ,activated ,lang_key, activation_key, authorities)
VALUES('3','admin','$2a$10$gSAhZrxMllrbgj/kkK9UceBPpChGWJA7SYIb1Mqo.n5aNLq1/oRrC','','Administrator','admin@localhost',true,'en','', {'ROLE_USER', 'ROLE_ADMIN'});

yupoint>INSERT INTO user_by_login (login, id)
VALUES('admin','3');

Answer 3

Cassandra 中的所有标识符（表名、列名等）不区分大小写，除非您将它们括在引号中每次引用它们时。 DataStax documentation on this

因为这往往很乏味，所以大多数人使用snake_case 来命名表和列，例如network_data 和network_type。如果你用引号括起来，这些标识符将继续出现在所有DESCRIBE 输出中的引号中：

cqlsh:testdb> DESCRIBE TABLES;
table1  table2  network_data  "networkData"  table5

我已将您的查询调整为使用大写字母，并已在本地成功测试：

const createTable = (
  `CREATE TABLE IF NOT EXISTS testdb."networkData" (
    latitude DOUBLE, 
    longitude DOUBLE, 
    "allowsVoIP" BOOLEAN, 
    speed DOUBLE, 
    uuid TEXT, 
    timestamp TIMESTAMP PRIMARY KEY, 
    "networkType" TEXT, 
    "carrierName" TEXT, 
    altitude DOUBLE, 
    "macAddress" TEXT, 
    "publicIP" TEXT, 
    "ssidLabel" TEXT, 
    "networkInterfaces" TEXT)`
);

const recordCommand = (
  `INSERT INTO testdb."networkData" (
    latitude, 
    longitude, 
    "allowsVoIP", 
    speed, 
    uuid, 
    timestamp, 
    "networkType",
    "carrierName", 
    altitude, 
    "macAddress", 
    "publicIP", 
    "ssidLabel", 
    "networkInterfaces"
  ) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)`
);

const params = [
  request.body.latitude,
  request.body.longitude,
  request.body.allowsVoIP,
  request.body.speed,
  request.body.uuid,
  request.body.timestamp,
  request.body.networkType,
  request.body.carrierName,
  request.body.altitude,
  request.body.macAddress,
  request.body.publicIP,
  request.body.ssidLabel,
  request.body.networkInterfaces,
];

const selectData = `SELECT * FROM testdb."networkData"`;

client.connect()
  .then(() => client.execute(createTable))
  .then(() => client.execute(recordCommand, params, { prepare: true }))
  .then(() => client.execute(selectData))
  .then(result => {
    let count = result.rows.length
    if (count > 0)
      console.log(`Total rows : ${count}`)
    else console.log("No rows")
  })
  .catch(error => console.log(error));