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RelationalDatabase   
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RelationalDatabase

Listing of Supported Databases »
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represents schema information about a relational database.

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gives the complete schema of the database referenced by db.

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RelationalDatabase[{table1 table2,…},db]

gives schema information related to the tables tablei.

Details and Options

  • In RelationalDatabase[db] or RelationalDatabase[tables,db], the database can be specified using DatabaseReference[…], URL[…] or File[…].
  • RelationalDatabase[…]["prop"] can be used to access database-level properties. These include:
  • "Tables"the list of table names
    "Connection"the DatabaseReference object
  • RelationalDatabase[…]["table",prop] can be used to access table-level properties. These include:
  • "Columns"the list of column names
    "PrimaryKey"the primary key constraint as an association
    "ForeignKeys"the list of foreign keys to other tables
    		"UniquenessConstraints"the list of uniqueness constraints for values in columns
    		"Indexes"the list of indexed columns
    All
  • the association of all table-level properties
  • RelationalDatabase[…]["table","PrimaryKey",prop] can be used to access the properties of the primary key:
  • "Columns"the columns that constitute the primary key
    "ConstraintName"the name of the constraint associated with the primary key
  • RelationalDatabase[…]["table","ForeignKeys"] gives a list of associations with the following elements:
  • "ToTable"the destination table of the foreign keys
    "FromColumns"the columns in the source table that map to columns in the destination table
    "ToColumns"the columns in the destination table that match the "FromColumns" in the source table
  • RelationalDatabase[…]["table","Indexes"] gives a list of associations that include the following elements:
  • "Columns"the columns taken to be unique together
    "IndexName"the name of the index
  • RelationalDatabase[…]["table","UniquenessConstraints"] gives a list of associations with the following elements:
  • "Columns"the columns whose combined values are taken to be unique
    "ConstraintName"the name of the uniqueness constraint
  • RelationalDatabase[…]["table","column",prop] can be used to access column-level properties. These include:
  • "NativeTypeString"the native type of the data stored in the column
    "Nullable"whether the column can contain Missing values
    Allthe association of all column-level properties
  • RelationalDatabase has the following option:
  • IncludeRelatedTables Falsewhether to include tables referenced by foreign keys

Examples

open allclose all

Basic Examples  (2)Summary of the most common use cases

Construct a RelationalDatabase object:

In[1]:=1
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https://wolfram.com/xid/0elvo4rd06qglx6-r57l0s
Out[1]=1

Find out what tables are present in the database:

In[2]:=2
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https://wolfram.com/xid/0elvo4rd06qglx6-m0jonl
Out[2]=2

Construct a RelationalDatabase with a subset of the tables:

In[1]:=1
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https://wolfram.com/xid/0elvo4rd06qglx6-wkfx8f
Out[1]=1

Scope  (6)Survey of the scope of standard use cases

Construct a RelationalDatabase object:

In[1]:=1
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https://wolfram.com/xid/0elvo4rd06qglx6-ig8xx2
Out[1]=1

Extract schema information:

In[2]:=2
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https://wolfram.com/xid/0elvo4rd06qglx6-itltmy
Out[2]=2

Extract information about a table:

In[3]:=3
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https://wolfram.com/xid/0elvo4rd06qglx6-f5072d
Out[3]=3

Extract information about a column:

In[4]:=4
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https://wolfram.com/xid/0elvo4rd06qglx6-4xtar6
Out[4]=4

Available properties at each level:

In[5]:=5
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https://wolfram.com/xid/0elvo4rd06qglx6-qri3vi
Out[5]=5
In[6]:=6
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https://wolfram.com/xid/0elvo4rd06qglx6-7ehbvr
Out[6]=6
In[7]:=7
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https://wolfram.com/xid/0elvo4rd06qglx6-lc9rsm
Out[7]=7

Show the connection used to inspect the database:

In[8]:=8
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https://wolfram.com/xid/0elvo4rd06qglx6-h0lu4e
Out[8]=8

Use DatabaseReference to refer to the database:

In[1]:=1
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https://wolfram.com/xid/0elvo4rd06qglx6-577awc
Out[1]=1

Use a database URL to refer to the database:

In[1]:=1
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https://wolfram.com/xid/0elvo4rd06qglx6-tyjq65
Out[1]=1

If the database is file based, it can be referenced as a File expression:

In[1]:=1
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https://wolfram.com/xid/0elvo4rd06qglx6-n0j8ar
Out[1]=1

Inspect only certain tables:

In[1]:=1
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https://wolfram.com/xid/0elvo4rd06qglx6-w3s7qr
Out[1]=1

The resulting object only has three tables:

In[2]:=2
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https://wolfram.com/xid/0elvo4rd06qglx6-eisq03
Out[2]=2

Construct a RelationalDatabase object:

In[1]:=1
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https://wolfram.com/xid/0elvo4rd06qglx6-5g8x2o
Out[1]=1

Get information about foreign keys for a given table:

In[2]:=2
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https://wolfram.com/xid/0elvo4rd06qglx6-p94la0
Out[2]=2

Get the database descriptor of a column type:

In[3]:=3
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https://wolfram.com/xid/0elvo4rd06qglx6-dte2sf
Out[3]=3

Extract all properties at the table level as an association:

In[4]:=4
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https://wolfram.com/xid/0elvo4rd06qglx6-kyjsa0
Out[4]=4

Extract all properties at the column level as an association:

In[5]:=5
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https://wolfram.com/xid/0elvo4rd06qglx6-03h1if
Out[5]=5

Options  (1)Common values & functionality for each option

IncludeRelatedTables  (1)

When inspecting only a subset of the tables, you might find references to other tables in the constraints:

In[1]:=1
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https://wolfram.com/xid/0elvo4rd06qglx6-e0zsnt
Out[1]=1

Set IncludeRelatedTables to True to include those in the object:

In[2]:=2
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https://wolfram.com/xid/0elvo4rd06qglx6-xp7vj7
Out[2]=2

The resulting object has more tables than you requested:

In[3]:=3
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https://wolfram.com/xid/0elvo4rd06qglx6-8g97l
Out[3]=3

Applications  (1)Sample problems that can be solved with this function

Construct a RelationalDatabase object:

In[1]:=1
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https://wolfram.com/xid/0elvo4rd06qglx6-vdda6
Out[1]=1

Construct an EntityStore from it:

In[2]:=2
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https://wolfram.com/xid/0elvo4rd06qglx6-fbzaue
Out[2]=2

Register the EntityStore:

In[3]:=3
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https://wolfram.com/xid/0elvo4rd06qglx6-eshjaz
Out[3]=3

Perform a query:

In[4]:=4
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https://wolfram.com/xid/0elvo4rd06qglx6-m6brmt
Out[4]=4

Properties & Relations  (1)Properties of the function, and connections to other functions

Visualize the structure of the foreign keys of a database:

In[1]:=1
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https://wolfram.com/xid/0elvo4rd06qglx6-4hyral
Out[1]=1
In[2]:=2
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https://wolfram.com/xid/0elvo4rd06qglx6-2ccsxv
Out[2]=2

Possible Issues  (2)Common pitfalls and unexpected behavior

Manually editing a RelationalDatabase might result in an object that does not reflect the state of the database. For this reason, it is currently not allowed:

In[1]:=1
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https://wolfram.com/xid/0elvo4rd06qglx6-ubybla
Out[1]=1

When inspecting only a subset of the tables, you might find references to other tables in the constraints:

In[1]:=1
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https://wolfram.com/xid/0elvo4rd06qglx6-jywc6x
Out[1]=1

Set IncludeRelatedTables to True to include those in the object:

In[2]:=2
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https://wolfram.com/xid/0elvo4rd06qglx6-y5zdwf
Out[2]=2

The resulting object has more tables than you requested:

In[3]:=3
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https://wolfram.com/xid/0elvo4rd06qglx6-cwy8wx
Out[3]=3
Wolfram Research (2019), RelationalDatabase, Wolfram Language function, https://reference.wolfram.com/language/ref/RelationalDatabase.html.
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Wolfram Research (2019), RelationalDatabase, Wolfram Language function, https://reference.wolfram.com/language/ref/RelationalDatabase.html.

Text

Wolfram Research (2019), RelationalDatabase, Wolfram Language function, https://reference.wolfram.com/language/ref/RelationalDatabase.html.

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Wolfram Research (2019), RelationalDatabase, Wolfram Language function, https://reference.wolfram.com/language/ref/RelationalDatabase.html.

CMS

Wolfram Language. 2019. "RelationalDatabase." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/RelationalDatabase.html.

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Wolfram Language. 2019. "RelationalDatabase." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/RelationalDatabase.html.

APA

Wolfram Language. (2019). RelationalDatabase. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/RelationalDatabase.html

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Wolfram Language. (2019). RelationalDatabase. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/RelationalDatabase.html

BibTeX

@misc{reference.wolfram_2025_relationaldatabase, author="Wolfram Research", title="{RelationalDatabase}", year="2019", howpublished="\url{https://reference.wolfram.com/language/ref/RelationalDatabase.html}", note=[Accessed: 25-May-2025 ]}

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@misc{reference.wolfram_2025_relationaldatabase, author="Wolfram Research", title="{RelationalDatabase}", year="2019", howpublished="\url{https://reference.wolfram.com/language/ref/RelationalDatabase.html}", note=[Accessed: 25-May-2025 ]}

BibLaTeX

@online{reference.wolfram_2025_relationaldatabase, organization={Wolfram Research}, title={RelationalDatabase}, year={2019}, url={https://reference.wolfram.com/language/ref/RelationalDatabase.html}, note=[Accessed: 25-May-2025 ]}

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@online{reference.wolfram_2025_relationaldatabase, organization={Wolfram Research}, title={RelationalDatabase}, year={2019}, url={https://reference.wolfram.com/language/ref/RelationalDatabase.html}, note=[Accessed: 25-May-2025 ]}