betteer format db-service/cql-functions

db-service/lib/cql-functions.js

@@ -1,59 +1,50 @@
-const cds = require('@sap/cds')
+'use strict'
 
 // OData: https://docs.oasis-open.org/odata/odata/v4.01/odata-v4.01-part2-url-conventions.html#sec_CanonicalFunctions
 const StandardFunctions = {
-  /**
-   * Generates SQL statement that produces a boolean value indicating whether the search term is contained in the given columns
-   * @param {string} ref
-   * @param {string} arg
-   * @returns {string}
-   */
-  search: function (ref, arg) {
-    if (!('val' in arg)) throw new Error(`Only single value arguments are allowed for $search`)
-    // only apply first search term, rest is ignored
-    const sub = /("")|("(?:[^"]|\\")*(?:[^\\]|\\\\)")|(\S*)/.exec(arg.val)
-    let val
-    try {
-      val = (sub[2] ? JSON.parse(sub[2]) : sub[3]) || ''
-    } catch {
-      val = sub[2] || sub[3] || ''
-    }
-    arg.val = arg.__proto__.val = val
-    const refs = ref.list
-    const { toString } = ref
-    return '(' + refs.map(ref2 => this.contains(this.tolower(toString(ref2)), this.tolower(arg))).join(' or ') + ')'
-  },
-  /**
-   * Generates SQL statement that produces the length of a given string
-   * @param {string} x
-   * @returns {string}
-   */
-  length: x => `length(${x})`,
+  // ==============================
+  // Aggregation Functions
+  // ==============================
+
   /**
    * Generates SQL statement that produces the average of a given expression
-   * @param {string} x
-   * @returns {string}
+   * @param {string} x - The expression to average
+   * @returns {string} - SQL statement
    */
   average: x => `avg(${x})`,
-  /**
-   * Generates SQL statement that produces a string with all provided strings concatenated
-   * @param  {...string} args
-   * @returns {string}
-   */
-  concat: (...args) => args.map(a => (a.xpr ? `(${a})` : a)).join(' || '),
 
   /**
    * Generates SQL statement that produces the number of elements in a given collection
-   * @param {string} x
-   * @returns {string}
+   * @param {string} x - The collection input
+   * @returns {string} - SQL statement
    */
   count: x => `count(${x?.val || x || '*'})`,
+
   /**
    * Generates SQL statement that produces the number of distinct values of a given expression
-   * @param {string} x
-   * @returns {string}
+   * @param {string} x - The expression input
+   * @returns {string} - SQL statement
    */
   countdistinct: x => `count(distinct ${x.val || x || '*'})`,
+
+  // ==============================
+  // String Functions
+  // ==============================
+
+  /**
+   * Generates SQL statement that produces the length of a given string
+   * @param {string} x - The string input
+   * @returns {string} - SQL statement
+   */
+  length: x => `length(${x})`,
+
+  /**
+   * Generates SQL statement that produces a string with all provided strings concatenated
+   * @param  {...string} args - The strings to concatenate
+   * @returns {string} - SQL statement
+   */
+  concat: (...args) => args.map(a => (a.xpr ? `(${a})` : a)).join(' || '),
+
   /**
    * Generates SQL statement that produces the substring of a given string
    * @example
@@ -62,89 +53,115 @@ const StandardFunctions = {
    * @example
    * // returns 'b'
    * {func:'substring',args:[{val:'abc'},{val:1},{val:1}]}
-   * @param {string} x
-   * @param {string} y
-   * @param {string} z
-   * @returns {string}
+   * @param {string} x - The string input
+   * @param {string} y - The starting position
+   * @param {string} z - The length of the substring
+   * @returns {string} - SQL statement
    */
   substring: (x, y, z) =>
     z
-      ? `substr( ${x}, case when ${y} < 0 then length(${x}) + ${y} + 1 else ${y} + 1 end, ${z} )`
-      : `substr( ${x}, case when ${y} < 0 then length(${x}) + ${y} + 1 else ${y} + 1 end )`,
+      ? `substr(${x}, case when ${y} < 0 then length(${x}) + ${y} + 1 else ${y} + 1 end, ${z})`
+      : `substr(${x}, case when ${y} < 0 then length(${x}) + ${y} + 1 else ${y} + 1 end)`,
+
   /**
    * Generates SQL statement that produces the lower case value of a given string
-   * @param {string} x
-   * @returns {string}
+   * @param {string} x - The string input
+   * @returns {string} - SQL statement
    */
   tolower: x => `lower(${x})`,
+
   /**
    * Generates SQL statement that produces the upper case value of a given string
-   * @param {string} x
-   * @returns {string}
+   * @param {string} x - The string input
+   * @returns {string} - SQL statement
    */
   toupper: x => `upper(${x})`,
+
   /**
    * Generates SQL statement that produces the trimmed value of a given string
-   * @param {string} x
-   * @returns {string}
+   * @param {string} x - The string input
+   * @returns {string} - SQL statement
    */
   trim: x => `trim(${x})`,
 
+  // ==============================
   // Arithmetic Functions
+  // ==============================
+
   /**
    * Generates SQL statement that produces the rounded up value of a given number
-   * @param {string} x
-   * @returns {string}
+   * @param {string} x - The number input
+   * @returns {string} - SQL statement
    */
   ceiling: x => `ceil(${x})`,
+
   /**
    * Generates SQL statement that produces the rounded down value of a given number
-   * @param {string} x
-   * @returns {string}
+   * @param {string} x - The number input
+   * @returns {string} - SQL statement
    */
   floor: x => `floor(${x})`,
+
   /**
    * Generates SQL statement that produces the rounded value of a given number
-   * @param {string} x
-   * @param {string} p precision
-   * @returns {string}
+   * @param {string} x - The number input
+   * @param {string} p - The precision
+   * @returns {string} - SQL statement
    */
   round: (x, p) => `round(${x}${p ? `,${p}` : ''})`,
 
+  // ==============================
   // Date and Time Functions
+  // ==============================
 
   /**
    * Generates SQL statement that produces current point in time (date and time with time zone)
-   * @returns {string}
+   * @returns {string} - SQL statement
    */
   now: function () {
     return this.session_context({ val: '$now' })
   },
+
   /**
-   * maximum date time value
-   * @returns {string}
+   * Maximum date time value
+   * @returns {string} - SQL statement
    */
-  maxdatetime: () => "'9999-12-31T23:59:59.999Z'",
+  maxdatetime: () => `'9999-12-31T23:59:59.999Z'`,
+
   /**
-   * minimum date time value
-   * @returns {string}
+   * Minimum date time value
+   * @returns {string} - SQL statement
    */
-  mindatetime: () => "'0001-01-01T00:00:00.000Z'",
+  mindatetime: () => `'0001-01-01T00:00:00.000Z'`,
 }
 
 const HANAFunctions = {
-  // https://help.sap.com/docs/SAP_HANA_PLATFORM/4fe29514fd584807ac9f2a04f6754767/f12b86a6284c4aeeb449e57eb5dd3ebd.html
-
   /**
    * Generates SQL statement that calls the session_context function with the given parameter
-   * @param {string} x session variable name or SQL expression
-   * @returns {string}
+   * @param {string} x - The session variable name or SQL expression
+   * @returns {string} - SQL statement
    */
   session_context: x => `session_context('${x.val}')`,
 
-  // Time functions
+  /**
+   * Generates SQL statement for the current date
+   * @param {string} [p] - Optional parameter
+   * @returns {string} - SQL statement
+   */
   current_date: p => (p ? `current_date(${p})` : 'current_date'),
+
+  /**
+   * Generates SQL statement for the current time
+   * @param {string} [p] - Optional parameter
+   * @returns {string} - SQL statement
+   */
   current_time: p => (p ? `current_time(${p})` : 'current_time'),
+
+  /**
+   * Generates SQL statement for the current timestamp
+   * @param {string} [p] - Optional parameter
+   * @returns {string} - SQL statement
+   */
   current_timestamp: p => (p ? `current_timestamp(${p})` : 'current_timestamp'),
 }