jdbc

Prepared statement Parameter index out of range (0 < 1 )

由 两盒软妹~` 提交于 2020-12-25 08:53:13
问题 Am not expert on web application, recently am writing a small webapp for my mobile app using servlets. My agenda is to receive data from client, and to put it into db. everything is running fine except, my database insert statement,which am trying to achieve using PreparedStatement. // This is how my insert statement looks like private String INSERT_INTO_DEVICES = "INSERT INTO travlemate.devices (owner," + "deviceid,gcmid) VALUES (?,?,?)"; // This is how am trying to insert PreparedStatement

Oracle Connection Pool Class

由 ╄→гoц情女王★ 提交于 2020-12-25 04:47:38
问题 I want to setup a connection pool for a Oracle DB in a Helper class. public class DbConnection { // Data source for the pooled connection private static OracleDataSource dataSource; // Host private static final String dbHost = "bla"; // Port private static final String dbPort = "1521"; // DBname private static final String database = "orcl"; // DBuser private static final String dbUser = "bla"; // DBpassword private static final String dbPassword = "bla"; static {

ResultSet getFetchSize() doesn't seem to work?

由 人盡茶涼 提交于 2020-12-25 01:02:56
问题 I'm having trouble with the getFetchSize() function. I simply need to know if the SQL query has returned zero rows. I've tried this simple statement: if (rs.getFetchSize()==0) System.out.println("HEADLINE"); where rs is of the ResultSet type. The above code doesn't seem to work. It always prints the message whether rs is empty or not. I checked the SQL query itself and it correctly returned non-empty result when rows existed. Any thoughts on how I can determine whether the query has returned

Error When Setting up H2 Database

由 廉价感情. 提交于 2020-12-23 14:36:27
问题 I have been getting this error when I'm starting my application which on start up reads some data from a table: org.h2.jdbc.JdbcSQLException: Unknown data type: "ENUM"; SQL statement: CREATE CACHED TABLE PUBLIC.POWERPLANT( POWERPLANTID INT NOT NULL, ORGNAME VARCHAR(25) NOT NULL, ISACTIVE BOOL NOT NULL, MINPOWER INT NOT NULL, MAXPOWER INT NOT NULL, RAMPRATE INT, RAMPRATESECS INT, POWERPLANTTYPE ENUM('OnOffType','RampUpType'), CREATEDAT TIMESTAMP NOT NULL, UPDATEDAT TIMESTAMP NOT NULL ) [50004

Error When Setting up H2 Database

由 别来无恙 提交于 2020-12-23 14:29:48
问题 I have been getting this error when I'm starting my application which on start up reads some data from a table: org.h2.jdbc.JdbcSQLException: Unknown data type: "ENUM"; SQL statement: CREATE CACHED TABLE PUBLIC.POWERPLANT( POWERPLANTID INT NOT NULL, ORGNAME VARCHAR(25) NOT NULL, ISACTIVE BOOL NOT NULL, MINPOWER INT NOT NULL, MAXPOWER INT NOT NULL, RAMPRATE INT, RAMPRATESECS INT, POWERPLANTTYPE ENUM('OnOffType','RampUpType'), CREATEDAT TIMESTAMP NOT NULL, UPDATEDAT TIMESTAMP NOT NULL ) [50004

Java JDBC 基础

由 为君一笑 提交于 2020-12-17 06:25:00
JDBC API 包含以下几个核心部分: 1:JDBC 驱动 2:Connections (连接) 3:Statements (声明) 4:Result Sets (结果集) JDBC: 打开数据库连接 Loading the JDBC Driver(加载数据库驱动) 在打开数据库连接前必须先加载数据库驱动 Class.forName("driverClassName"); Opening the Connection(打开连接) String url = "jdbc:mysql://127.0.0.1:3306/appName"; String user = "root"; String password = "root"; Connection connection = DriverManager.getConnection(url,user,password); Closing the Connection(关闭连接) connection.close(); JDBC:查询数据库 对数据库进行操作,你需要创建SQL Statement,然后发送至数据库,得到返回结果. Statement statement = connection.createStatement(); 创建Statement后执行查询 String sql = "SELECT * FROM people"

Load dataframe from pyspark

由 倾然丶 夕夏残阳落幕 提交于 2020-12-15 05:23:56
问题 I am trying to connect to MS SQL DB from PySpark using spark.read.jdbc import os from pyspark.sql import * from pyspark.sql.functions import * from pyspark import SparkContext; from pyspark.sql.session import SparkSession sc = SparkContext.getOrCreate() spark = SparkSession(sc) df = spark.read \ .format('jdbc') \ .option('url', 'jdbc:sqlserver://local:1433') \ .option('user', 'sa') \ .option('password', '12345') \ .option('dbtable', '(select COL1, COL2 from tbl1 WHERE COL1 = 2)') then I do df

Load dataframe from pyspark

由 好久不见. 提交于 2020-12-15 05:23:06
问题 I am trying to connect to MS SQL DB from PySpark using spark.read.jdbc import os from pyspark.sql import * from pyspark.sql.functions import * from pyspark import SparkContext; from pyspark.sql.session import SparkSession sc = SparkContext.getOrCreate() spark = SparkSession(sc) df = spark.read \ .format('jdbc') \ .option('url', 'jdbc:sqlserver://local:1433') \ .option('user', 'sa') \ .option('password', '12345') \ .option('dbtable', '(select COL1, COL2 from tbl1 WHERE COL1 = 2)') then I do df

Configure a `DataSource` to connect to a managed Postgres server on Digital Ocean with SSL/TLS encryption

由 ＊爱你＆永不变心＊ 提交于 2020-12-15 03:49:29
问题 I am trying the managed database service on DigitalOcean.com, having created a Postgres instance. Digital Ocean defaults to requiring remote connections be made with SSL (actually TLS) encryption. How does one configure a JDBC DataSource implementation for providing connections to such a database server? This Question is similar to Produce a DataSource object for Postgres JDBC, programmatically but adds the specific elements of SSL/TLS encryption and using a managed database remotely. 回答1:

Configure a `DataSource` to connect to a managed Postgres server on Digital Ocean with SSL/TLS encryption

由 自古美人都是妖i 提交于 2020-12-15 03:48:59
问题 I am trying the managed database service on DigitalOcean.com, having created a Postgres instance. Digital Ocean defaults to requiring remote connections be made with SSL (actually TLS) encryption. How does one configure a JDBC DataSource implementation for providing connections to such a database server? This Question is similar to Produce a DataSource object for Postgres JDBC, programmatically but adds the specific elements of SSL/TLS encryption and using a managed database remotely. 回答1:
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