I have got a form with 3 input fields (date, time, telephone) and I need to build a database where I can select date and time from drop down menu (two separate tables where one has got date values another one has got time values).
Both of these date and time tables have another column with value 0 or 1. If this value is 0 you can select that time, but if the value is 1 it can't: e.g. I select the date and it shows me available times, so then I can add a telephone number and submit all values to another table (date, time, telephone I guess) - but if the time is already taken it can't be selected.
If all time slots are selected already you can't select that date because the date value changes from 0 to 1.
It's my first database project so I don't really understand things in database architecture yet. I don't need the code I'll figure it out, I just need to see how the database looks with all the tables, primary keys etc.
Related
The table doesn't have any date time column. I want to if there is any inbuilt keyword which can does that.
I want to know all commits done after a particular date.
If flashback is enabled on the database you can get records on the table in an around a particular date range in Oracle.(It purely depends on if its enabled and for how long the flashback needs to be kept)
You can query to see the data in the table as of 3 days back as follows
select *
from table as of timestamp sysdate-3
I think title is clear what is my problem. I am working with MySql I just wanted to know what was the first registration on my website and when I sorted the table according to timestamp, the id of people who registered on the website were not true. The Image bellow will show what do I mean:
and this is the code what phpMyAdmin created:
SELECT *
FROM `table`
ORDER BY `table`.`timestamp` ASC
LIMIT 0 , 30
whats wrong with my table time? and why id is not ordered same as timestamps
If we assume that id is an auto-increment field, then this is almost certainly due to the fact that timestamp column is not assigned at the same physical time the id column is assigned. For example, if you have a multi-page registration from a website application, the initial object may be inserted into the database to contain the initial data fields gathered on the first page. But perhaps the timestamp is only set after the final page of registration is complete. So depending on the time the user takes to complete registration, the timestamp can be out-of-sync with the id order.
There are multiple ways to work around this. One way is to assign timestamp when the record is first inserted into the database, or you could use a DB insert trigger to populate the timestamp field instead.
There is also the possibility that timestamp represents the date and time the user last modified their profile (or otherwise caused modification of the database record). In this case, the timestamp could be changing to a "future" value while the id stays constant.
PostPosted: 09 May 2014 22:26
Post subject: Determine table based on prompt
Hello,
I have three fact tables. First table holds current data, FACT_CUSTOMER_CURRENT. Other two tables hold historical snapshots. For example, one of these table holds last 60 days' records- FACT_CUSTOMER_DAILY. The other table holds data for the last day of the months.-FACT_CUSTOMER_MONTHLY
I want to add a date prompt. If the user selects yesterday as a prompt value, report should bring value from first table which holds current data (FACT_CUSTOMER_CURRENT). If user enters 28.02.2014, the report should retrieve data from FACT_CUSTOMER_MONTHLY. I tried to use context and aggregate awareness, but I could not be successful.
Can you help me?
Kind regards
There's no direct, easy way to do what you want.
Aggregate Awareness is useful for selecting a table based on the selection of objects in a query, but it does not support dynamic selection of tables based on values in a prompt.
If yesterday's data will only exist in fact_customer_current, then you can use this method: In your report, create a UNION query. One query includes objects from fact_customer_current, and the other from fact_customer_monthly. They both have an identical prompt on the appropriate date field. When a user enters yesterday's date, the first UNION query will return data but the second one won't. Likewise for date before yesterday, the first UNION will return no data but the second one will. This solution requires that the tables are correctly indexed such that a query on a date that isn't in the table will return quickly.
I am looking for some design techniques to achieve the following:
A 3-part serial number that is generated upon record entry. Format Example: 25-001-14
The number is used to track yearly records from various locations.
The first part states the location the record is associated with, this would be a user input during record creation.
The second part is the record number, I would like for this to be automatically generated, but needs to be sequential and separate for each location and needs to reset each year.
The third part is the two digit number for the year the record was created in. I would like this to be automatically generated if possible. Note: I am currently not concerned with when this cycles back around and I face redundant data issues.
I'm thinking I would like records to be stored in multiple tables that are separated by location, if this would help things!
Any ideas would be greatly welcomed.
I think I would use 3 key fields - one field each for location, record and year. The location and year fields would be created when you get the input to create new records. I would set up a query to find the last record number used by location and year and use that query to assign the new record number when you create a new record. The concatenation of the 3 fields would be the key you described.
With a key field for location, separate tables are not necessary unless that's useful for other reasons. I would probably use just one table - you can always filter the records by location anytime you need to.
I started building a search engine monitor. I'm pulling data from the google rest api into a mysql database with the following fields: date, search-keyword, domain, url, position.
Now I got into trouble querying and outputting the data for charting. The results go up and down, new results from google come into the list which haven't been there on the first day. However for charting I have to assign the first days at least blank values to output a chart.
What I do right now: First I select every domain showing up in the period. Lets say the for the keyword searchengine I get the domains wikipedia.org, ixquick.com, yahoo.com, searchenginewatch.com When I make another request for ever domain to query an array of rankings grouped by day. leading to the ...
Problem: Is where any query (mysql/nosql) which returns for each day an average and if where is no row a default value e.g. blank?
Result should look like:
dates={01/01/2014,02,03,04,05,06,07,08,...,31}
wikipedie={1,1,1,1,1,1,1,1,...,1}
yahoo = {"","",7,5,3,3,3,...,3}
You can create a date table, select the date range you'd like, and outer join your data to it, filling in 0s for values that do not exist for a given term/date.
Edit:
Some more details.
1) Create a table that has a row for every date +- 10 years (or whatever is appropriate). You can make this one column if you'd like, or many columns (date, month, year, etc.). The second approach makes this extensible if you want to summarize by various rollups in the future.
2) Outer join your table to the date table and use a NVL statement to coerce any null averages to 0.
3) Profit!
If your results are grouped by date, how can MySQL know there's (for example) 31 days in that month?
On the other hand, you can somehow fill the holes in PHP by loop through the array and fill a zero if the value does not exist.