MEAL officer learning log

It's a one of great videos I used when have been preparing for my first MEAL officer position interview. The video not focused on some app or tecnologie qusetions, but it can give you an advice, what kind of topics you may meet at the interview. If you aren't focused on the senior DA position, you should repeat what you have already known, but there are too many different information and this video can give a hint about priority knowledge areas.  

Throughout the video, the differences between the various JOIN types are highlighted, including the type of data that is returned and how the JOINs handle NULL values. The video also provides examples of each type of JOIN using sample data and demonstrates how the results differ based on the type of JOIN used. In addition to explaining the different types of JOIN statements, the video also emphasizes the importance of considering the data model when working with JOINs. Specifically, the video highlights the case of a swimming club database, where JOIN statements are used to combine data from multiple tables such as members, trainers, sport clubs and events. By considering the relationships between these tables and the data they contain, database professionals can make informed decisions about which type of JOIN to use and how to optimize their queries. This underscores the fact that JOIN statements are not just technical tools, but also require careful consideration of the underlyi...

The first 15 minutes of the video are devoted to a brief overview of the trainer's git repository with few SQL jupyter notebooks. We can use Azure Data Studio to interract with DB  

SELECT column, another_column, … FROM mytable WHERE condition(s) ORDER BY column ASC/DESC LIMIT num_limit OFFSET num_offset; SELECT - shows what the specific data we want to find. Available parameters: * (all columns) or [columns list] FROM - explains to the DB server, what a table we want to process. Available parameter: table name WHERE - explains to the DB server, what a rules we want to use when filter column(s) entity. Here, we can use logical unary NOT, LIKE, IS or binary AND, OR operators. Also, math comparison operators are available: =, !=, < <=, >, >=. We can use expressions, like: BETWEEN 20 AND 50 ORDER BY - describe way to items display order (alphabetic by value grows or falls) LIMIT - restrict display items count. OFFSET - explains to the DB server, how many items we want to pass before display found rows. We can use DISTINCT instruction after SELECT operator to trim duplicates inside output dataset.

A little bit of database design introduction. The video describes how to convert our raw data into 1NF and organizing it into separate tables. It also demonstrates the use of the SELECT operator to retrieve related data from different tables without the need for an INNER JOIN instruction.  

There are articles about a temp table's role in a database functioning process, their location in SSMS structure and a temp table creation procedure. Also, the speaker considers some GO operator using aspects and its place in the query design process. We obtain advices of IDENTITY constraint using for different stages of DB table development.  

SQLBolt.com is a free interactive website that offers a comprehensive and easy-to-follow tutorial on SQL, which is the standard language for managing relational databases. The website provides step-by-step explanations, examples, and exercises for beginners to advanced learners to develop their SQL skills. SQLBolt.com covers topics such as querying, filtering, sorting, joining, grouping, and modifying data using SQL statements. Users can also test their knowledge and receive immediate feedback on the website's interactive platform.

In this video we'll find out how to get connection string for Python ODBC connection in three ways: manual, with SSMS and using online generators. Also, the speaker talks about query executing and committing at examples SELECT and INSERT queries.

Constraints NOT NULL Constraint: Ensures that a column cannot have NULL value. DEFAULT Constraint: Provides a default value for a column when none is specified. UNIQUE Constraint: Ensures that all values in a column are different. PRIMARY Key : Uniquely identified each rows/records in a database table. FOREIGN Key : Uniquely identified a rows/records in any another database table. CHECK Constraint: The CHECK constraint ensures that all values in a column satisfy certain conditions. INDEX : Use to create and retrieve data from the database very quickly Data Integrity Entity Integrity : There are no duplicate rows in a table. Domain Integrity : Enforces valid entries for a given column by restricting the type, the format, or the range of values. Referential Integrity : Rows cannot be deleted which are used by other records. User-Defined Integrity : Enforces some specific business rules that do not fall into entity, domain, or referential integrity.

The speaker discussed possible strategies for using the SSIS Wizard in SQL Server Management Studio for over an hour. They provided a superficial overview of the available data sources for importing data and the role of ODBC drivers in the process.  

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The video is a descriptive one that focuses on providing an overview of three often used DML operators, namely the SELECT, INSERT, and UPDATE operators. These operators are commonly used in SQL queries to retrieve, insert, and update data from a database. The video highlights how these operators can be used to manipulate a small dataset, making it a great resource for individuals who are just starting to learn SQL or those who are looking to brush up on their skills. At the same time, using such a small data set is a disadvantage, as our results are not sufficiently significant. Towards the end of the video, the same query is executed in SQL and coded with Python, providing viewers with an opportunity to compare and contrast how the same task can be accomplished using different languages.

It's not enought informative video, but it can be useful for beginners, who don't know what start with. The video contains short description of SQL language basics and gives instruction how to install SQL engine + SQL Server Management Studio from Microsoft.