{"id":7353,"date":"2019-10-21T09:26:55","date_gmt":"2019-10-21T09:26:55","guid":{"rendered":"https:\/\/www.devopsschool.com\/blog\/?p=7353"},"modified":"2019-10-28T06:24:29","modified_gmt":"2019-10-28T06:24:29","slug":"what-is-the-best-way-to-learn-sql-for-data-analyst","status":"publish","type":"post","link":"https:\/\/www.devopsschool.com\/blog\/what-is-the-best-way-to-learn-sql-for-data-analyst\/","title":{"rendered":"What is the best way to learn SQL for data analyst?"},"content":{"rendered":"\n

Fundamental SQL Statements<\/h3>\n\n\n\n
  1. Create<\/strong>: creating a basic table involves naming the table and defining its columns and each column’s data type.
    Syntax<\/strong> :
    CREATE TABLE “table_name”(
    “column 1” “data type for column 1” [column 1 constraint(s)],
    “column 2” “data type for column 2” [column 2 constraint(s)],
    ……
    “column n”
    [“table constraint(s)”]);
    <\/li><\/ol>\n\n\n\n

    Example : <\/strong>
    create table Engineer_table (
    Cust_id int,
    First_name varchar,
    Last_name varchar,
    age int,
    email_id varchar);
    )<\/p>\n\n\n\n

    Constraints define the type of data which will be entered into the table column.
    Now I am defining the type of Constraints, so please look below for a better understanding of constraints:<\/p>\n\n\n\n

    1. NOT NULL<\/strong> Constraint<\/strong>: Ensures that a column cannot have NULL value.<\/li>
    2. DEFAULT Constraint<\/strong>: Provides a default value for a column when none is specified.<\/li>
    3. UNIQUE Constraint<\/strong>: Ensures that all values in a column are different.<\/li>
    4. CHECK Constraint<\/strong>: Makes sure that all values in a column satisfy certain criteria.<\/li>
    5. Primary Key Constraint<\/strong>: Used to uniquely identify a row in the table.<\/li>
    6. Foreign Key Constraint<\/strong>: used to ensure referential integrity of the data.<\/li><\/ol>\n\n\n\n

      Keys<\/strong><\/h3>\n\n\n\n
      • A primary key is used to uniquely identify each row in a table and consist of one or more columns on a table.<\/li>
      • When multiple columns are used as a primary key, they are called a composite key.<\/li>
      • A foreign key is a column( or columns) that references a column (most often the primary key) of another table.<\/li><\/ul>\n\n\n\n

        2. INSERT<\/em><\/strong>: The INSERT INTO statement is used to add new records into a database table.<\/p>\n\n\n\n

        Syntax<\/strong>:
        INSERT INTO “table_name” (“column1″,”column2”,\u2026) VALUES(“value1″,”value2”,\u2026);<\/p>\n\n\n\n

        Example:
        Single row<\/strong> (without column names specified<\/em>)
        INSERT INTO customer_table
        VALUES(1, ‘chandan’,’Kumar’,23,’chandan@devopsschool.com’);

        Single row<\/strong> (with column name specified<\/em>)
        INSERT INTO customer_table(cust_id,first_name,last_name,age,email_id)
        VALUES(2, ‘Ajay’,’Kumar’,24,’ajay@devopsschool.com’);

        Multiple rows<\/em><\/strong>
        INSERT INTO customer_table
        VALUES (1,’ck’,’dk’,35,’az@xyz.com’),
        (2,’ak’,’pj’,36,’hg@xyz.com’);<\/p>\n\n\n\n


        <\/p>\n","protected":false},"excerpt":{"rendered":"

        Fundamental SQL Statements Create: creating a basic table involves naming the table and defining its columns and each column’s data type.Syntax : CREATE TABLE “table_name”( “column 1” “data type for… <\/p>\n","protected":false},"author":8,"featured_media":7463,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_joinchat":[],"footnotes":""},"categories":[5150],"tags":[5445,5448,5446,421,5447,3242],"class_list":["post-7353","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-php","tag-fundamental","tag-insert","tag-query","tag-sql","tag-table","tag-unique"],"_links":{"self":[{"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/posts\/7353","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/comments?post=7353"}],"version-history":[{"count":5,"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/posts\/7353\/revisions"}],"predecessor-version":[{"id":7375,"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/posts\/7353\/revisions\/7375"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/media\/7463"}],"wp:attachment":[{"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/media?parent=7353"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/categories?post=7353"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/tags?post=7353"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}