gooderp18绿色标准版
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  1. <?xml version="1.0" encoding="UTF-8" standalone="no"?>
  2. <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>36.23. domains</title><link rel="stylesheet" type="text/css" href="stylesheet.css" /><link rev="made" href="pgsql-docs@lists.postgresql.org" /><meta name="generator" content="DocBook XSL Stylesheets V1.79.1" /><link rel="prev" href="infoschema-domain-udt-usage.html" title="36.22. domain_udt_usage" /><link rel="next" href="infoschema-element-types.html" title="36.24. element_types" /></head><body><div xmlns="http://www.w3.org/TR/xhtml1/transitional" class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center">36.23. <code xmlns="http://www.w3.org/1999/xhtml" class="literal">domains</code></th></tr><tr><td width="10%" align="left"><a accesskey="p" href="infoschema-domain-udt-usage.html" title="36.22. domain_udt_usage">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="information-schema.html" title="Chapter 36. The Information Schema">Up</a></td><th width="60%" align="center">Chapter 36. The Information Schema</th><td width="10%" align="right"><a accesskey="h" href="index.html" title="PostgreSQL 12.4 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="infoschema-element-types.html" title="36.24. element_types">Next</a></td></tr></table><hr></hr></div><div class="sect1" id="INFOSCHEMA-DOMAINS"><div class="titlepage"><div><div><h2 class="title" style="clear: both">36.23. <code class="literal">domains</code></h2></div></div></div><p>
  3. The view <code class="literal">domains</code> contains all domains defined in the
  4. current database. Only those domains are shown that the current user has
  5. access to (by way of being the owner or having some privilege).
  6. </p><div class="table" id="id-1.7.6.27.3"><p class="title"><strong>Table 36.21. <code class="literal">domains</code> Columns</strong></p><div class="table-contents"><table class="table" summary="domains Columns" border="1"><colgroup><col /><col /><col /></colgroup><thead><tr><th>Name</th><th>Data Type</th><th>Description</th></tr></thead><tbody><tr><td><code class="literal">domain_catalog</code></td><td><code class="type">sql_identifier</code></td><td>Name of the database that contains the domain (always the current database)</td></tr><tr><td><code class="literal">domain_schema</code></td><td><code class="type">sql_identifier</code></td><td>Name of the schema that contains the domain</td></tr><tr><td><code class="literal">domain_name</code></td><td><code class="type">sql_identifier</code></td><td>Name of the domain</td></tr><tr><td><code class="literal">data_type</code></td><td><code class="type">character_data</code></td><td>
  7. Data type of the domain, if it is a built-in type, or
  8. <code class="literal">ARRAY</code> if it is some array (in that case, see
  9. the view <code class="literal">element_types</code>), else
  10. <code class="literal">USER-DEFINED</code> (in that case, the type is
  11. identified in <code class="literal">udt_name</code> and associated
  12. columns).
  13. </td></tr><tr><td><code class="literal">character_maximum_length</code></td><td><code class="type">cardinal_number</code></td><td>
  14. If the domain has a character or bit string type, the declared
  15. maximum length; null for all other data types or if no maximum
  16. length was declared.
  17. </td></tr><tr><td><code class="literal">character_octet_length</code></td><td><code class="type">cardinal_number</code></td><td>
  18. If the domain has a character type, the maximum possible length
  19. in octets (bytes) of a datum; null for all other data types.
  20. The maximum octet length depends on the declared character
  21. maximum length (see above) and the server encoding.
  22. </td></tr><tr><td><code class="literal">character_set_catalog</code></td><td><code class="type">sql_identifier</code></td><td>Applies to a feature not available in <span class="productname">PostgreSQL</span></td></tr><tr><td><code class="literal">character_set_schema</code></td><td><code class="type">sql_identifier</code></td><td>Applies to a feature not available in <span class="productname">PostgreSQL</span></td></tr><tr><td><code class="literal">character_set_name</code></td><td><code class="type">sql_identifier</code></td><td>Applies to a feature not available in <span class="productname">PostgreSQL</span></td></tr><tr><td><code class="literal">collation_catalog</code></td><td><code class="type">sql_identifier</code></td><td>
  23. Name of the database containing the collation of the domain
  24. (always the current database), null if default or the data type
  25. of the domain is not collatable
  26. </td></tr><tr><td><code class="literal">collation_schema</code></td><td><code class="type">sql_identifier</code></td><td>
  27. Name of the schema containing the collation of the domain, null
  28. if default or the data type of the domain is not collatable
  29. </td></tr><tr><td><code class="literal">collation_name</code></td><td><code class="type">sql_identifier</code></td><td>
  30. Name of the collation of the domain, null if default or the
  31. data type of the domain is not collatable
  32. </td></tr><tr><td><code class="literal">numeric_precision</code></td><td><code class="type">cardinal_number</code></td><td>
  33. If the domain has a numeric type, this column contains the
  34. (declared or implicit) precision of the type for this domain.
  35. The precision indicates the number of significant digits. It
  36. can be expressed in decimal (base 10) or binary (base 2) terms,
  37. as specified in the column
  38. <code class="literal">numeric_precision_radix</code>. For all other data
  39. types, this column is null.
  40. </td></tr><tr><td><code class="literal">numeric_precision_radix</code></td><td><code class="type">cardinal_number</code></td><td>
  41. If the domain has a numeric type, this column indicates in
  42. which base the values in the columns
  43. <code class="literal">numeric_precision</code> and
  44. <code class="literal">numeric_scale</code> are expressed. The value is
  45. either 2 or 10. For all other data types, this column is null.
  46. </td></tr><tr><td><code class="literal">numeric_scale</code></td><td><code class="type">cardinal_number</code></td><td>
  47. If the domain has an exact numeric type, this column contains
  48. the (declared or implicit) scale of the type for this domain.
  49. The scale indicates the number of significant digits to the
  50. right of the decimal point. It can be expressed in decimal
  51. (base 10) or binary (base 2) terms, as specified in the column
  52. <code class="literal">numeric_precision_radix</code>. For all other data
  53. types, this column is null.
  54. </td></tr><tr><td><code class="literal">datetime_precision</code></td><td><code class="type">cardinal_number</code></td><td>
  55. If <code class="literal">data_type</code> identifies a date, time,
  56. timestamp, or interval type, this column contains the (declared
  57. or implicit) fractional seconds precision of the type for this
  58. domain, that is, the number of decimal digits maintained
  59. following the decimal point in the seconds value. For all
  60. other data types, this column is null.
  61. </td></tr><tr><td><code class="literal">interval_type</code></td><td><code class="type">character_data</code></td><td>
  62. If <code class="literal">data_type</code> identifies an interval type,
  63. this column contains the specification which fields the
  64. intervals include for this domain, e.g., <code class="literal">YEAR TO
  65. MONTH</code>, <code class="literal">DAY TO SECOND</code>, etc. If no
  66. field restrictions were specified (that is, the interval
  67. accepts all fields), and for all other data types, this field
  68. is null.
  69. </td></tr><tr><td><code class="literal">interval_precision</code></td><td><code class="type">cardinal_number</code></td><td>
  70. Applies to a feature not available
  71. in <span class="productname">PostgreSQL</span>
  72. (see <code class="literal">datetime_precision</code> for the fractional
  73. seconds precision of interval type domains)
  74. </td></tr><tr><td><code class="literal">domain_default</code></td><td><code class="type">character_data</code></td><td>Default expression of the domain</td></tr><tr><td><code class="literal">udt_catalog</code></td><td><code class="type">sql_identifier</code></td><td>Name of the database that the domain data type is defined in (always the current database)</td></tr><tr><td><code class="literal">udt_schema</code></td><td><code class="type">sql_identifier</code></td><td>Name of the schema that the domain data type is defined in</td></tr><tr><td><code class="literal">udt_name</code></td><td><code class="type">sql_identifier</code></td><td>Name of the domain data type</td></tr><tr><td><code class="literal">scope_catalog</code></td><td><code class="type">sql_identifier</code></td><td>Applies to a feature not available in <span class="productname">PostgreSQL</span></td></tr><tr><td><code class="literal">scope_schema</code></td><td><code class="type">sql_identifier</code></td><td>Applies to a feature not available in <span class="productname">PostgreSQL</span></td></tr><tr><td><code class="literal">scope_name</code></td><td><code class="type">sql_identifier</code></td><td>Applies to a feature not available in <span class="productname">PostgreSQL</span></td></tr><tr><td><code class="literal">maximum_cardinality</code></td><td><code class="type">cardinal_number</code></td><td>Always null, because arrays always have unlimited maximum cardinality in <span class="productname">PostgreSQL</span></td></tr><tr><td><code class="literal">dtd_identifier</code></td><td><code class="type">sql_identifier</code></td><td>
  75. An identifier of the data type descriptor of the domain, unique
  76. among the data type descriptors pertaining to the domain (which
  77. is trivial, because a domain only contains one data type
  78. descriptor). This is mainly useful for joining with other
  79. instances of such identifiers. (The specific format of the
  80. identifier is not defined and not guaranteed to remain the same
  81. in future versions.)
  82. </td></tr></tbody></table></div></div><br class="table-break" /></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="infoschema-domain-udt-usage.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="information-schema.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="infoschema-element-types.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">36.22. <code class="literal">domain_udt_usage</code> </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> 36.24. <code class="literal">element_types</code></td></tr></table></div></body></html>
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