SQL : PostgreSQL

  Aggregate Functions Like most other relational database products,  PostgreSQL  supports  aggregate functions . An aggregate function computes a single result from multiple input rows. For example, there are aggregates to compute the  count ,  sum ,  avg  (average),  max  (maximum) and  min  (minimum) over a set of rows. As an example, we can find the highest low-temperature reading anywhere with: SELECT max(temp_lo) FROM weather; max ----- 46 (1 row) If we wanted to know what city (or cities) that reading occurred in, we might try: SELECT city FROM weather WHERE temp_lo = max(temp_lo); WRONG but this will not work since the aggregate  max  cannot be used in the  WHERE  clause. (This restriction exists because the  WHERE  clause determines which rows will be included in the aggregate calculation; so obviously it has to be evaluated before aggregate functions are computed.) However, as is o...

Test / Course challenge


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The function =CONCATENATE(A7, " ", B7) would return "John Quincy Adams." The correct function to use here would be CONCATENATE, which you can use to combine strings. Using CONCAT with these arguments would resolve this correctly in Microsoft Excel, but return an error in Google Sheets. Going forward, you can use this distinction to write proper spreadsheet functions.

CONCAT function make table more concise , easier to work. and other variables we can use CANCATENATE function are name, date, address, and many more.
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Congratulations on completing this hands-on activity! A good response would include how combining data with CONCAT and CONCATENATE helps you simplify and clean data by combining string data from multiple cells into a single cell. 

In order to properly and efficiently analyze data, the data has to be clean and understandable. Data analysts use functions like CONCAT to make data easier to work with, which may require combining multiple cells. Coming up, you will learn more spreadsheet functions that will help you analyze data in spreadsheets.


 

*Course challenge*

Latest Submission Grade 87.5%
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Downloading data from a database into a .CSV file, then importing it into a spreadsheet, will enable you to process and analyze the small dataset effectively.

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You could ask your supervisor or a colleague for guidance. Asking questions helps you learn and avoid mistakes.

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You could ask your supervisor or a colleague for guidance. Asking questions helps you learn and avoid mistakes.

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The function begins with an equal sign (=), then the word AVERAGE. The range is all of column E, represented by E:E.

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The share phase involves creating data visualizations, preparing your presentation, and communicating your findings to stakeholders.

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The share phase involves creating data visualizations, preparing your presentation, and communicating your findings to stakeholders.

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The share phase involves creating data visualizations, preparing your presentation, and communicating your findings to stakeholders.

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The correct syntax is WHERE zip_code = 81137. WHERE indicates where to look for information. The column name is zip_code. And the database is being asked to return only records matching zip code 81137.

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It’s your responsibility as a data analyst to make sure your analysis is fair. Although many zip codes do reflect diverse populations, a better choice would be to include data about people who live in multiple zip codes.

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A business task is the question or problem data analysis answers for a business.

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Subject-matter experts can offer insights into the business problem, identify inconsistencies in the analysis, and validate the choices being made.

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Subject-matter experts can offer insights into the business problem, identify inconsistencies in the analysis, and validate the choices being made.

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Subject-matter experts can offer insights into the business problem, identify inconsistencies in the analysis, and validate the choices being made.

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A pie chart is used to represent the proportions of certain data categories compared to the whole. A line chart would be effective for tracking trends over time, such as people attending fewer appointments as they get older.

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