Showing posts with the label hadoop structural data

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SQL Interview Success: Unlocking the Top 5 Frequently Asked Queries

 Here are the five top commonly asked SQL queries in the interviews. These you can expect in Data Analyst, or, Data Engineer interviews. Top SQL Queries for Interviews 01. Joins The commonly asked question pertains to providing two tables, determining the number of rows that will return on various join types, and the resultant. Table1 -------- id ---- 1 1 2 3 Table2 -------- id ---- 1 3 1 NULL Output ------- Inner join --------------- 5 rows will return The result will be: =============== 1  1 1   1 1   1 1    1 3    3 02. Substring and Concat Here, we need to write an SQL query to make the upper case of the first letter and the small case of the remaining letter. Table1 ------ ename ===== raJu venKat kRIshna Solution: ========== SELECT CONCAT(UPPER(SUBSTRING(name, 1, 1)), LOWER(SUBSTRING(name, 2))) AS capitalized_name FROM Table1; 03. Case statement SQL Query ========= SELECT Code1, Code2,      CASE         WHEN Code1 = 'A' AND Code2 = 'AA' THEN "A" | "A

Sqoop Real Use in Hadoop Framework

Why Sqoop you need while working on Hadoop-The Sqoop and its primary reason is to import data from structural data sources such as Oracle/DB2 into HDFS(also called Hadoop file system). To our readers, I have collected a good video from Edureka which helps you to understand the functionality of Sqoop. The comparison between Sqoop and Flume How name come for Sqoop Sqoop word came from SQL+HADOOP=SQOOP. And Sqoop is a data transfer tool. The main use of Sqoop is to import and export a large amount of data from RDBMS to HDFS and vice versa. List of basic Sqoop commands Codegen- It helps to generate code to interact with database records. Create-hive-table- It helps to Import a table definition into a hive Eval- It helps to evaluate SQL statement and display the results Export-It helps to export an HDFS directory into a database table Help- It helps to list the available commands Import- It helps to import a table from a database to HDFS Import-all-tables- It