Read from database using STRICT type mapping
Updated: Sep 3, 2023
This example shows how to read a database table in Java using STRICT type mapping which is defined by Oracle/Sun and implemented as the default by most JDBC drivers. This strategy uses the types in java.sql.Types
alone.
You can reference JDBC Type Mapping guide for more details on mapping JDBC/database types to fields in records.
Input SQL File
DROP TABLE jewellery IF EXISTS; CREATE TABLE jewellery ( title VARCHAR(100), published BOOLEAN, variant_inventory_qty INTEGER, gift_card TINYINT, variant_price FLOAT, variant_compare_at_price DOUBLE, min_price DECIMAL(5,0), max_price DECIMAL(30,10), height DECIMAL(15,0), width DECIMAL(8,0), weight DECIMAL(25,0), taxable CHAR, created_on TIMESTAMP, launch_date DATE, launch_time TIME ); INSERT INTO jewellery (title, published, variant_inventory_qty, gift_card, variant_price, variant_compare_at_price, min_price, max_price, height, width, weight, created_on, launch_date, launch_time) VALUES ('7 Shakra Bracelet', false, 5, 0, 123.123, 1234.1234, 100, 9765490, 12345, 98765, 12345678901234567890, '2022-09-25 21:35:13', '2022-09-25', '09:30:17'), ('Anchor Bracelet Mens', true, 10, 1, 987.987, 5678.5678, 300, 1256793, 67890, 456235, 98765432109876543210, '2022-12-21 21:35:13', '2023-01-12', '09:30:17'), ('Bangle Bracelet', true, 10, 0, 123.123, 1234.1234, 100, 9765490, 556677, 99441166, 11223344556677889900, '2022-09-25 21:35:13', '2022-09-25', '09:30:17') ;
Java Code Listing
package com.northconcepts.datapipeline.examples.cookbook; import java.io.File; import com.northconcepts.datapipeline.core.StreamWriter; import com.northconcepts.datapipeline.internal.jdbc.JdbcFacade; import com.northconcepts.datapipeline.jdbc.JdbcConnectionFactory; import com.northconcepts.datapipeline.jdbc.JdbcReader; import com.northconcepts.datapipeline.jdbc.JdbcValueReader; import com.northconcepts.datapipeline.job.Job; public class ReadFromDatabaseUsingStrictMapping { public static void main(String[] args) { JdbcConnectionFactory connectionFactory = JdbcConnectionFactory.wrap("org.h2.Driver", "jdbc:h2:mem:ReadFromDatabaseUsingOpinionatedMapping;MODE=MySQL", "sa", ""); JdbcFacade jdbcFacade = new JdbcFacade(connectionFactory); System.out.println("====================================Start: Executing script===================================="); jdbcFacade.executeFile(new File("example/data/input", "jewellery.sql")); System.out.println("====================================End: Executing script===================================="); JdbcReader reader = new JdbcReader(connectionFactory, "SELECT * FROM jewellery;"); reader.setValueReader(JdbcValueReader.STRICT); Job.run(reader, new StreamWriter(System.out)); } }
Code Walkthrough
- Database connection parameters are specified using JdbcConnectionFactory and JdbcFacade.
- The input SQL query is executed using
jdbcFacade.executeFile()
method. - JdbcReader is created to obtain records from the database table.
- JdbcValueReader type is set to
STRICT
. It means mapping database types to Java types based only onjava.sql.Types
as defined by Sun/Oracle. - Job.run() is used to transfer the data from
reader
toStreamWriter(System.out)
. See how to compile and run data pipeline jobs.
Console Output
====================================Start: Executing script==================================== execute file /IdeaProjects/DataPipeline-Examples/example/data/input/jewellery.sql execute: DROP TABLE jewellery IF EXISTS - recordsAffected=0 execute: CREATE TABLE jewellery ( title VARCHAR(100), published BOOLEAN, variant_inventory_qty INTEGER, gift_card TINYINT, variant_price FLOAT, variant_compare_at_price DOUBLE, min_price DECIMAL(5,0), max_price DECIMAL(30,10), height DECIMAL(15,0), width DECIMAL(8,0), weight DECIMAL(25,0), taxable CHAR, created_on TIMESTAMP, launch_date DATE, launch_time TIME ) - recordsAffected=0 execute: INSERT INTO jewellery (title, published, variant_inventory_qty, gift_card, variant_price, variant_compare_at_price, min_price, max_price, height, width, weight, created_on, launch_date, launch_time) VALUES ('7 Shakra Bracelet', false, 5, 0, 123.123, 1234.1234, 100, 9765490, 12345, 98765, 12345678901234567890, '2022-09-25 21:35:13', '2022-09-25', '09:30:17'), ('Anchor Bracelet Mens', true, 10, 1, 987.987, 5678.5678, 300, 1256793, 67890, 456235, 98765432109876543210, '2022-12-21 21:35:13', '2023-01-12', '09:30:17'), ('Bangle Bracelet', true, 10, 0, 123.123, 1234.1234, 100, 9765490, 556677, 99441166, 11223344556677889900, '2022-09-25 21:35:13', '2022-09-25', '09:30:17') - recordsAffected=3 ====================================End: Executing script==================================== 23:49:23,932 DEBUG [main] datapipeline:37 - DataPipeline v8.2.0 by North Concepts Inc. ----------------------------------------------- 0 - Record (MODIFIED) { 0:[TITLE]:STRING=[7 Shakra Bracelet]:String 1:[PUBLISHED]:BOOLEAN=[false]:Boolean 2:[VARIANT_INVENTORY_QTY]:INT=[5]:Integer 3:[GIFT_CARD]:INT=[0]:Integer 4:[VARIANT_PRICE]:DOUBLE=[123.123]:Double 5:[VARIANT_COMPARE_AT_PRICE]:DOUBLE=[1234.1234]:Double 6:[MIN_PRICE]:BIG_DECIMAL=[100]:BigDecimal 7:[MAX_PRICE]:BIG_DECIMAL=[9765490]:BigDecimal 8:[HEIGHT]:BIG_DECIMAL=[12345]:BigDecimal 9:[WIDTH]:BIG_DECIMAL=[98765]:BigDecimal 10:[WEIGHT]:BIG_DECIMAL=[12345678901234567890]:BigDecimal 11:[TAXABLE]:STRING=[null] 12:[CREATED_ON]:DATETIME=[2022-09-25 21:35:13.0]:Timestamp 13:[LAUNCH_DATE]:DATE=[2022-09-25]:Date 14:[LAUNCH_TIME]:TIME=[09:30:17]:Time } ----------------------------------------------- 1 - Record (MODIFIED) { 0:[TITLE]:STRING=[Anchor Bracelet Mens]:String 1:[PUBLISHED]:BOOLEAN=[true]:Boolean 2:[VARIANT_INVENTORY_QTY]:INT=[10]:Integer 3:[GIFT_CARD]:INT=[1]:Integer 4:[VARIANT_PRICE]:DOUBLE=[987.987]:Double 5:[VARIANT_COMPARE_AT_PRICE]:DOUBLE=[5678.5678]:Double 6:[MIN_PRICE]:BIG_DECIMAL=[300]:BigDecimal 7:[MAX_PRICE]:BIG_DECIMAL=[1256793]:BigDecimal 8:[HEIGHT]:BIG_DECIMAL=[67890]:BigDecimal 9:[WIDTH]:BIG_DECIMAL=[456235]:BigDecimal 10:[WEIGHT]:BIG_DECIMAL=[98765432109876543210]:BigDecimal 11:[TAXABLE]:STRING=[null] 12:[CREATED_ON]:DATETIME=[2022-12-21 21:35:13.0]:Timestamp 13:[LAUNCH_DATE]:DATE=[2023-01-12]:Date 14:[LAUNCH_TIME]:TIME=[09:30:17]:Time } ----------------------------------------------- 2 - Record (MODIFIED) { 0:[TITLE]:STRING=[Bangle Bracelet]:String 1:[PUBLISHED]:BOOLEAN=[true]:Boolean 2:[VARIANT_INVENTORY_QTY]:INT=[10]:Integer 3:[GIFT_CARD]:INT=[0]:Integer 4:[VARIANT_PRICE]:DOUBLE=[123.123]:Double 5:[VARIANT_COMPARE_AT_PRICE]:DOUBLE=[1234.1234]:Double 6:[MIN_PRICE]:BIG_DECIMAL=[100]:BigDecimal 7:[MAX_PRICE]:BIG_DECIMAL=[9765490]:BigDecimal 8:[HEIGHT]:BIG_DECIMAL=[556677]:BigDecimal 9:[WIDTH]:BIG_DECIMAL=[99441166]:BigDecimal 10:[WEIGHT]:BIG_DECIMAL=[11223344556677889900]:BigDecimal 11:[TAXABLE]:STRING=[null] 12:[CREATED_ON]:DATETIME=[2022-09-25 21:35:13.0]:Timestamp 13:[LAUNCH_DATE]:DATE=[2022-09-25]:Date 14:[LAUNCH_TIME]:TIME=[09:30:17]:Time } ----------------------------------------------- 3 records