Database Definition and 136 Threads

  1. W

    I Temporal Database and its Relational Algebra

    Hi all, Just curious on whether temporal databases are designed in the same way as "standard" relational databases, so that queries on temporal databases are wffs in temporal logic , i.e., using Until, Release and all other unary operators , and the query outputs is the set of models for the...
  2. W

    Why are tables not showing up in Object explorer in database

    Hi all, I successfully created (scripted) a database in MS SQL Server 2012. My problem is that while the database itself is listed in the object explorer , the tables from the database are not. The database I scripted did not contain actual data, i.e., there were no 'Insert' statements. Is this...
  3. W

    "Upgradeability/Scalability" of GUI , "non-script Database?

    Hi All, I have been asking around on the "upgradeability" or scalability of GUI -based databases, e.g. Access (using QBE) vs scripted ones, e.g., back-end SQL -based databases (no C# or PHP -based interface). I keep hearing scripted ones are preferrable in the sense of being easier to...
  4. W

    Importing flat files (e.g.) Excel directly into SQL Database

    Hi all, I have a bunch of legacy files I am trying to import directly into an .sql database. Is there a way of doing this other than by using Microsoft's import/export Wizard?
  5. Serena

    Find Hexane, MEK, EA Densities at 40° | Database

    I need hexane, MEK and EA densities at 40 degrees. Do you know a good database where to find them?
  6. Serena

    Where Can I Find Reliable Solubility Data for Various Mixtures and Temperatures?

    HI, Do you have any suggestion for a good solubility database? I tried IUPAC-NIST but I can't find the data I need there (water-toluene, water-hexane, water-MEK mixtures at 40°C). I am also looking for the densities of the pure solvents at 40°C. Thank you
  7. W

    Renaming Columns in DB Table: Apex SQL or Examine Dependenci

    Hi All, Just curious as to what those with experience in creating databases believe is the best method when renaming databases: using Apex SQL , which (supposedly) automatically checks for dependencies or just sitting down , looking at the dependencies and doing the changes one by one as needed...
  8. S

    'Operand type clash: numeric is incompatible with uniqueiden

    Could use some help figuring out the error Operand type clash: numeric is incompatible with uniqueidentifier which points to the specified line below CREATE PROCEDURE AddPartner @name NVARCHAR(50), @email NVARCHAR(254), @new_guid UNIQUEIDENTIFIER OUTPUT AS BEGIN SET NOCOUNT ON...
  9. 24forChromium

    Where Can I Find Molar Absorptivity Data for Chromate and Dichromate Ions?

    I need the molar absorptivity data of chromate and dichromate ions at various wavelengths, can anyone suggest a database or something like that?
  10. W

    Protocol for PKs (Primary Keys) with Null Entries?

    Hi all :I have the table Emp (EmpNum PK, EmpLastNM, EmpEducation, EmpDependent, EmpEducation,...EMpHireDate) which I want to normalize and then I want to do an ERD for it. I must break this into tables one for which , it seems, I cannot have a non-null PK: Now EmpDependent is both...
  11. W

    Syntax for DDL table design in MSSQLServer 2014.

    Hi all, I am learning DDL ( as opposed to GUI ) table design in MSSL2014. EDIT I am given a table printout and I want as an output the(a) DDL code that would output the given table. Sorry, I don't have a scanner nor the original file in my PC, I have a table diagram in a piece of paper. I...
  12. V

    Database mounted. ORA-01113: file 1 needs media recovery

    The only way to recover is from media backup? I know I cannot "rebuild" system datafile, but if I don't have a backup - I know shame on me! - Is there anyway to recover database?
  13. L

    Why Can't I Open My Database File?

    Can not open database file. When you open a written "Application Error" and all. I tried to import objects into a new database. Tables and queries were imported without a problem, but on the forms, reports and modules gives the same error. Standard recovery says that all recovered, but no result.
  14. W

    Relational DB: Examples of When 1:1 Should be Kept Seperate versus Together

    Hi All, The "best practices" in RDB on 1:1 relations between entities are that the two entities E1, E2 should be merged into a single one by default, i.e., unless there is an overwhelming reason to keep them separated. Can someone provide illustrating examples of when the two entities...
  15. W

    Relational DB :Relation-type Algebra?

    Hi, say we have entities A,B,C in a Relational Database. Is there a sort-of operational algebra that allows us to determine that if, say, A and B are in a many-many relation and B and C are in a 1-many relation, then A,C are in a certain relationship, i.e., a composition algebra between...
  16. O

    What is the Connection Between Physics, Chemistry, and Data Management?

    Hi! I was physics student in Switzerland, but was unsuccessful because of several Army duties in atomical-chemical troups. Physics and chemistry were my passions. Since, I re-oriented myself in computer science as a learner, and discovered a new passion in data management (nowadays databases...
  17. W

    Refs for Advance Data Base Books ( My Turn )

    Hi all, I guess now I am at the different end, after having replied to many requests for info on books. I do not have access ( ha-ha) to a library, though I do have access to a bookstore. I am looking for an intermediate-to-advanced book in Database. I have covered the basics: Normalization...
  18. P

    Exploring Nature: Joining Discussions on Software Testing and Astronomy

    I am looking forward to joining discussions here. My Backgroud is 2 years "applied physics", 5 years education for teaching in visual communication (art), 15 years experience as a database software developer. Now I am looking for a job as a software tester. Software Testing is similar to being...
  19. Omega0

    Where Can I Access a Database for Universe Mass Distribution and Movement?

    Hi, Where can I find a database with the mass distribution and its movement in the well-known universe? Best wishes, Jens
  20. W

    Functionally Determined and 1NF

    Hi All, Say we have a relation R ( i.e., a table in a relational DB ), which has a primary key PK, but R is not in 1 NF. I guess we then conclude that PK _does not_ functionally-determine the table, since, after the table is put in 1NF, PK is o longer the primary key, right? It seems...
  21. W

    Many to Many Relations in Database

    I am pulling my hair trying to find a straight answer to this, after looking it up in different books, websites: Say we have a many-to-many relationship in a RDB (Relational DB). Is there a standard way of creating a junction, bridge, etc. table? From what I know,. the bridge table will contain...
  22. W

    Functional Dependence (In Table/General)

    Hi all, hope this is the right forum. Please feel free to move it otherwise: I am confused on whether functional dependence can be determined uniquely by the particulars of a given table, or if it is determined in a more general sense So I have my relational table. Let A,B be attributes ...
  23. W

    [SQL] Referential Integrity Details

    Hi a probably dumb question on Referential Integrity: I think I understand the basic idea/motivation for it, but one thing I am confused about is this: just when/how do we declare a column in a given table T' to be a foreign key related to the primary key for table T? Is it when we...
  24. W

    [SQL] Way of Relating any two Tables?

    Hi all, Say we have a collection T_1, T_2,..., T_n of tables. I would like for any pair to be related. Would it work if I where to select any field, say the primary key PKT_1 for T_1 and insert it (albeit artificially) meaning include it as an attribute in every other table? If we did this...
  25. W

    [SQL] Order of Appearence in Query Results.

    Hi All, I know that if we use Select * , then the fields in the table will appear in the same order as listed. Same if we list all the fields manually, as in Select field1, field2,.., fieldn . Is it true that the order of the fields is preserved always (I can't think of other cases at this...
  26. W

    Difference Between Sort By, Order By & Group By

    Hi, just curious about the difference between the " Sort By " and " Order By" commands in database. I assume Sort by is used in QBE and "Order by" is used in SQL ? While we're at it, how about "Group By"? Thanks.
  27. Borg

    QuestionsCan I effectively use HDF5 with rusty math skills?

    Though one of my many internet searches, I ran across Hierarchical Data Formats (HDF) last year. It seems interesting but I feel like I'm in over my head a bit. I believe that some people here have use it and I'm looking for advice on getting started, what to watch for and how it's different...
  28. B

    How Should Manage Be Represented in an ER Diagram for a Video Rental Company?

    I am doing a ER Diagram for a class and having a lot of trouble with a specific piece of the sentence. Anyway, here is the business requirements we are diagramming: The video rental company has several branches throughout the USA. The data held on each branch is the branch address made up of...
  29. adjacent

    Transforming a text file to a database

    I have a list of contacts like this: Name ,Address:House ,Island ,Atoll 7777777 Name ,Address:House ,Island ,Atoll 7777777 Name ,Address:House ,Island ,Atoll 7777777 I have a large number of these and I want the details to be separated to different columns. Is there any program which...
  30. V

    Database of theories beyond the standard model?

    I am a programmer and physics fan. A speaker (Lawrence Krauss?) at https://origins.asu.edu/events/great-debate-parallel-realities-probing-fundamental-physics (not on youtube yet) said physics theories beyond the standard model are an under-determined problem. There are 7,000 theories that fit...
  31. R

    Molecular emission spectra database

    Hi, I am looking for online molecular emission spectra database for spectroscopic analysis of plasma. It would be great if searching in it is based on a wavelength of spectral lines/bands. For atomic spectra I found this database: http://physics.nist.gov/PhysRefData/ASD/lines_form.html But I...
  32. P

    Python How can I build a database in Python?

    Does anyone have a good tutorial or start-up advice for building a database in Python? The only database software I've ever used is Microsoft Access, but I've heard it's possible to build databases in Python. I was thinking I'd start off with a simple database: a few tables that can draw...
  33. H

    Hardware affect Database performance

    How would the CPU, RAM and disk storage of a Database server affect the performance of the Database?
  34. S

    How do I create and open a SQLite database in Windows?

    hi everyone , i downloaded SQLite files , i have in c:\windows\system32\sqlite 3 files: 1- sqlite.exe 2-sqlite.dll 3-sqlite.def my problem is that i can't create a database or open the one i created by the administrative tools .. as one of the website said that the way to create a...
  35. P

    Python How can I get specific elements from a tuple/list in Python without iterating?

    I am using python to get tuples from a db. I am doing cur.execute("Select Statement"); I use cur.fetchall to get the tuples. My question is how do you iterate over the returned tuples and store the columns into an array? I want to iterate over n tuples, not all the returned results...
  36. L

    What Are Ritz Wavelengths in the NIST Atomic Spectra Database?

    Hello all, What is mean the Ritz Wavelengths in the NIST Atomic Spectra Database? Why the Ritz or Observed value for some Wavelength are very different? Thanks, Lil
  37. J

    Help building a database of organic compounds used in pharmaceuticals

    Hello Guys, So I'm trying to build a database of organic compounds that are of interest to the pharmaceutical industry. Most importantly compounds containing heteroatoms (>= 15% by mass). Where do i start!? any good websites or books, with a useful appendix you can tell me about? I would...
  38. D

    Does anyone know a database for nth roots of unity

    I am typing up a latex document and I need to find roots of unity, lots of them, for numbers like say 42. I was just wondering if anyone knew of a database that had this stuff on hand rather than having to do it all by hand and worrying about having made some stupid algebra error.
  39. E

    Looking for atomic energy level database

    Hello,everyone! I want to know if there is database which can tell me the energy level diagram of atom. I have consulted NIST Atomic database,but I can't find energy level diagram. so anybody can help me ? I WANT to get the energy leverl diagram like hydrogen atom in modern books(potential...
  40. X

    C/C++ [C++] Database Handler (simple)

    Mod note: Instead of using HTML FONT and SIZE tags, just put [ code ] and [ /code ] tags around your code.[/color] Hi everyone. I have no idea how databases are usually done, but I figured I'd try to write an advanced I/O database in c++, but I wanted to make a database class that's fairly...
  41. M

    High-frequency time series database

    I'm choosing a database to write high-frequency time series data onto and have narrowed it down to MongoDB, Kyoto Cabinet or HDF5. I will be inserting 1200 rows of 8 entries per second, cumulating about 5 GB of data per day I'm estimating. Does anyone have experience between the three and...
  42. I

    Probability based on pre-entered database

    Greetings I have been working on database collection, and I'm trying to take it to the next level, as a calculator based on the pre-entered information The information would consist of many variable factor (around 8) This is only an example, and not related to the real statistical data...
  43. iamjon.smith

    Please Review Database Tables for Advanced Database Class

    After you have analyzed the existing material used by the company for their day-to-day duties, the current Access database, and the additional requirements that the current system does not meet, the following requirements entity/attributes have been compiled: Customer information is tracked...
  44. K

    Create Distributed Database w/ MySQL, MS SQL, Oracle & PostgreSQL

    I need to create a system using heterogeneous database. I must use at least 4 different database. My choice would be MySQL, MS SQL Server, Oracle and PostgreSQL since these are among the most popular and matured database or if you have any database that is more suitable please tell me...
  45. Z

    Programming language to use to make plots from a database?

    I am a graduate student who has basically no experience programming but I would like to learn so I decided to give myself a project. What I would like to do is build a web application that can plot data (2D & 3D) from a database. Once I get that far I would like to have the web application...
  46. D

    Is google search a Database management system ?

    Wasn't sure about where else to post this so I posted it here : I got into an argument with my friend about google search being a DBMS, I disagreed because it doesn't fit the definition that we were given or the one on wikipedia and a few more websites. All that google search does it query a...
  47. R

    Is There a Medline Equivalent for Physics Research Papers?

    In medicine and biology they have Medline which is a complete database of research papers---kind of a complete search engine of research papers in medicine and biology---which has free access to public. Is there anything comparable to this in physics---...
  48. S

    Compare and/or combine two Access database tables

    I have just discovered that two people have been typing into separate copies of 'the same' MS Access database for some while. It came to light when one said, "Why can't Jo see the changes I make?" Any suggestions on how to combine the two tables or at least compare them with a view to...
  49. N

    Mathematica How to create a database in Mathematica

    Hi All, I have to solve a system of non-linear equations for a wide range of parameter space. I'm using FindRoot which is sensitive to initial conditions so I have to do it by hand and by trial and error and plotting, rather than putting the equations in a loop or in a table. So what I...
  50. R

    Where can I find a comprehensive online database for stellar data analysis?

    I am looking for a On line or downloadable stellar highly detailed database. Nasa had a excellent one but seemed to remove it from (NASA Star and Exoplanet Database (NStED). Wiki has lots of detail on there website but its star by star basis.I want to analyse large batches of stellar data...
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