Oracle SQL - How to retrieve the ID Count difference between today vs yesterday

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I have a table that captures when a customer purchases a product. It captures a unique purchase id along with a timestamp of when the purchase was made.

I want to be able to query, the difference between how many purchases were taken today vs yesterday?

Not sure how to query this on oracle?

You can use conditional aggregation:

select sum(case when trunc(datecol) = trunc(sysdate - 1) then 1 else 0 end) as num_yesterday,
       sum(case when trunc(datecol) = trunc(sysdate) then 1 else 0 end) as num_today,
       sum(case when trunc(datecol) = trunc(sysdate) then 1
                when trunc(datecol) = trunc(sysdate - 1) then -1
           end) as diff
from t
where datecol >= trunc(sysdate - 1);

DATE queries using BETWEEN - Ask Tom, Developers and DBAs get help from Oracle experts on: DATE queries using code or SQL code is what is slow, this setting won't make a bit of difference! Now as for: "SQL book says that between should find dates min>=date<=max. select count(*) from my_big_table 1 select to_date(id,'yyyy-mm-dd') from temp1 I have a column called createdate of datetime datatype. I want to extract data between today and yesterday. select * from table1(nolock) where createdate ='2018-06-01' --not getting any output I

you can use the Group function to grouping the purchase day with timestamp information and count the purchase id.

select trunc(purchase_ts) Day, count(purchase_id) Count
from purchase
group by trunc(purchase_ts)
order by 1 

dba_hist_active_sess_history, SQL_ID, VARCHAR2(13), SQL identifier of the SQL statement that is currently being Populated only when the session was waiting for enqueues or a "buffer busy" wait. NUMBER, Time that the current session actually spent waiting for the event. CURRENT_OBJ#, NUMBER, Object ID of the object that the session is  This tip will explain the differences between the following COUNT function varieties: COUNT(*) vs. COUNT(1) vs. COUNT(column_name) to determine if there is a performance difference. Solution. There are more efficient ways than using the COUNT() function if the goal is just to retrieve the total row count from a table.

Using TRUNC on the column will prevent Oracle from using an index on that column (instead you would need a separate function-based index); instead use a CASE statement to test whether the date is between the start of the day and the start of the next day and then COUNT the values between those ranges:

         WHEN TRUNC( SYSDATE ) - INTERVAL '1' DAY <= your_date_column
         AND  your_date_coumn < TRUNC( SYSDATE )
         THEN 1
       ) AS count_for_yesterday,
         WHEN TRUNC( SYSDATE ) <= your_date_column
         AND  your_date_coumn < TRUNC( SYSDATE ) + INTERVAL '1' DAY
         THEN 1
       ) AS count_for_today
FROM   your_table
WHERE  TRUNC( SYSDATE ) - INTERVAL '1' DAY <= your_date_column
AND    your_date_coumn < TRUNC( SYSDATE ) + INTERVAL '1' DAY

SQL Query aggregation and subqueries - Ask Tom, Developers and DBAs get help from Oracle experts on: SQL Query stores information about items in a warehouse stored in different bins. I need to calculate two things: 1. 2. or do the join in the innermost (warehouse column) query like : RECORD_STATUS='CURRENT' 15 and = job_fk_id 16 and​  The following numeric example uses the BETWEEN condition to retrieve values within a numeric range. For example: SELECT * FROM customers WHERE customer_id BETWEEN 4000 AND 4999; This Oracle BETWEEN example would return all rows from the customers table where the customer_id is between 4000 and 4999 (inclusive). It is equivalent to the following

Pro Oracle SQL, If you need a yes or no response or just a short answer, closed questions suit that To demonstrate the differences between these three types, I ask the same you have to follow up with an identification question to get the answer you need. DEPARTMENT_ID NUMBER(4) SQL> select employee_id, count(*) job_ct 2  SQL COUNT( ) with All . In the following, we have discussed the usage of ALL clause with SQL COUNT() function to count only the non NULL value for the specified column within the argument. The difference between ‘*’(asterisk) and ALL are, '*' counts the NULL value also but ALL counts only NON NULL value. Example:

Troubleshooting Oracle Performance, count = number of times OCI procedure was executed cpu = cpu time in of buffers gotten for consistent read current = number of buffers gotten in current mode (usually for update) rows = number of rows processed by the fetch or execute Note that the ID of the SQL statement is available only as of Oracle Database 11g. Answer: Oracle supports date arithmetic and you can make expressions like "date1 - date2" using date subtraction to get the difference between the two dates. Once you have the date difference, you can use simple techniques to express the difference in days, hours, minutes or seconds.

How to compare two tables of data - Ask Tom, Developers and DBAs get help from Oracle experts on: How to compare two select count(*) that's why I asked for all data. now there is no timestamp or flag that will If I have two identical tables from two different databases and not much of SQL> select id,'In table 1, not in table 2' 2 from accounts 3 minus 4 select id  SQL HOME SQL Intro SQL Syntax SQL Select SQL Select Distinct SQL Where SQL And, Or, Not SQL Order By SQL Insert Into SQL Null Values SQL Update SQL Delete SQL Select Top SQL Min and Max SQL Count, Avg, Sum SQL Like SQL Wildcards SQL In SQL Between SQL Aliases SQL Joins SQL Inner Join SQL Left Join SQL Right Join SQL Full Join SQL Self Join SQL